Søren Roest Korsgaard

The Search for the Strückelmörder Continues in Hannover

Introduction

As reported in the article, “The Hunt for Hamburg’s Jack the Ripper,” a highly organized murderer has dismembered a sex worker with expert precision. He then disposed of her body parts, some of which had been sealed in blue garbage bags, in at least five locations, mostly within the city of Hamburg. Based on the available evidence, it was opined that the killer appeared experienced and that he had likely committed other violent offenses. The sensational nature of the Hamburg case started a torrent of news reports, flooding the residents of Germany. Journalists from the Hamburger Morgenpost caught on quickly and spotted strong parallels to a case from Hannover, 2010, where a sex worker was murdered, dismembered, and partially found in blue garbage bags.

From Hamburg to Hannover


On August 1, 2017, Maria Ngui, also known as Rosa, age 48, disappeared at around 2 p.m. from St. George, a highly populated and central city district within Hamburg. She was last seen walking together with a strong and big 50-55-year-old unidentified man, the presumed killer. Rosa, an occasional sex worker, lived primarily in Spain and spoke limited German. According to a fellow prostitute, she was vulnerable as she was known to accompany all potential sex customers. With unknown means, Rosa was killed and with expert precision, her body was dismembered into at least 17 parts, which the killer subsequently placed in strategic locations that had limited surveillance. The common denominator in all of the disposal sites is water, and the investigators considered the obvious inference that the killer was a sailor, fisher, or somehow else often associated with the areas.
Just a few decades ago, killers with multiple crimes scenes or dump sites had an obvious advantage to today where major cities are congested with government CCTV equipment, tourists taking pictures and filming with their smartphones, private dashcams, and cameras in- and outside stores, etc. Considering the immense sophistication of forensic science, DNA technology, fiber analysis, cell phone triangulation, and much more, it is remarkable that the police almost immediately admitted that they had no promising leads. The lack of evidence does not lean toward random chance, but it is the hallmark of a highly organized killer who is well-prepared, meticulous, minimizes risk, and likely has committed other assaults or murders and with time has polished his abilities, and thus learned from his past mistakes. With the exception of a disposal site at the Wittenbergen beach, the dump sites, paradoxically, were not low risk in the sense that the sites entailed a high degree of probability that people would discover the body parts. It appeared likely that the killer was motivated, in part, by excitement, and by a grandiose need to get known nationwide, perhaps even internationally. From this conclusion and by considering that the killer cut off the victim’s ears, it can be deduced that the dismemberment was primarily of the offensive type (motivated by psychological factors) rather than the defensive (motivated by a desire to get rid of forensic evidence). After the killing, a German reporter interviewed a St. George sex worker, Sunny, who revealed an alleged sex customer, matching the description of the killer, had attempted to persuade sex workers to accompany him to his home for whipping and bondage games [1]. Shortly after the case landed on the front page and was featured on the six o’clock news on all the major German TV stations, journalists noted possible forensic and circumstantial similarities between the Strückelmörder auf Hamburg and a brutal murderer from Hannover. Seven years earlier in 2010, shockwaves promulgated through Hannover’s prostitutes when body parts of a local prostitute were found underneath the Legion Bridge on the banks of the Ihme, a 26 km long river, which is a tributary of the 281 km long Leine River.

The Legion Bridge.

January 1, 2010, Hannover

On January 1, 2010, Monika Pawlak, age 24, celebrated New Year with her family in a pub on Elisenstrasse in Hannover-Leiden. She left at around 2 a.m. to continue her celebrations somewhere else [2]. Witnesses would later inform police officials that they had spotted her with the Stadtbahn, one of the city’s primary methods of public transportation, in the direction of the city center. Pawlak migrated in 1989 to Germany from Poland and was characterized by friends and coworkers as being naïve and of low cognitive functioning due to a childhood accident from which she never recovered. She regularly took cocaine and prostituted herself near Mehlstrasse in Hannover. After her trip with the Stadtbahn ended, her whereabouts remain unknown. On Saturday, January 2, two blue garbage bags were spotted underneath the Legion Bridge, next to the Ihne. Later, it was discovered that the bags contained some of Pawlak’s body parts.         

Crime scene reconstruction.

The investigation

At the morgue, the police discovered a tattoo of a rose on the victim’s back and decided to name the investigation: “Mordkommission Rose [3].” The blue plastic bags did not contain the entire body: Her arms and head were missing in addition to Pawlak’s clothes. An extensive search by divers and professionals with body dogs and sonar equipment through the Ihme, the 26 km long river running underneath the Legion Bridge, turned out empty handed.
Ultimately, following an exhaustive effort to identify the producer of the garbage bags, it was discovered that they were exclusively available through wholesale from Italy. The plastic had a low tear resistance, which indicated to investigators that the murder was impulsive as the killer had to use more than one plastic bag for each sack to prevent them from tearing apart [4].
Unlike the Hamburg case, there was in this instance much more evidence to work with, and initially the investigators were highly optimistic that their efforts would soon lead to the identification, arrest, and conviction of the killer. Their optimism especially grew when a forensic scientist extracted unidentified DNA from one of the plastic bags. The examination of the plastic bags also revealed microscopic evidence (hairs presumably) which indicated that dogs and cats lived in the residence where the victim had been killed and dismembered.
Optimism faded when none of the state databases furnished a DNA match. However, the scientist also discovered soil traces on one of the plastic bags that did not match the unique chemical properties of the soil from underneath the bridge. Officers then secretly collected soil samples from strategically selected areas in Hannover, a city covering over 200 square kilometers. When an expert delivered a report on Rainer Nöltker’s desk, head of the homicide division, his positive hunch reappeared as the report confirmed that the samples from the plastic bags were consistent with soil samples from Ihme-Zentrum, the center of Hannover. For undisclosed reasons police zoomed in on three 20-story high risers located in that area. Police acted promptly and conducted extensive DNA mass testing among the residents of the high risers, using surprise tactics which included knocking on doors and asking the residents if they were willing to submit their DNA [5]. Police also collected over one thousand DNA profiles from the Hannover-Leiden area whereof the victim celebrated New Year with her family. Much to the surprise of the killer’s pursuers, the perpetrator had somehow gone under the radar.

Posters did not lead to the killer’s apprehension. The bridge, which became the disposal site, can be seen in the background.

The Autopsy   

The coroner assigned to Mordkommission Rose made surprising discoveries during the autopsy. It was discovered that the body parts had been frozen when they were placed underneath the bridge [4]. An analysis of the victim’s blood showed that Pawlak had ingested cocaine just before her heart stopped. The killer had stabbed her to death. According to a later statement by the head of the homicide division, Rainer Nöltker, the dismemberment of the body had not been “very professional [4].”

A Suspect

In May, 2011, 15 months after the murder, a new witness, age 51, contacted the police upon learning that the garbage bags had been of the color blue. At 12:10 p.m., January 1, 2010, about 15 minutes walking distance from the dump site, she had seen a German looking man, slim, 180 cm tall, 35-45 years old, pulling two wooden sedges with bulky, blue plastic bags [6]. Importantly, the killer could not have transported the garbage bags by a vehicle to the Legion Bridge as there are no roads near it, but a sledge would have been an optimal method of transportation in the city of Hannover that had been covered with dense snow for weeks.

Reconstruction by the police.

Comparative Case Analysis

Linkage analysis is the process by which crimes are compared to determine if there is a likelihood that two or more crimes have been committed by the same offender due to distinctive behavioral factors or discrete connections. The analyst will establish and compare “physical evidence, victimology, crime scene characteristics, motivation, modus operandi (MO), and signature behaviors of each of the cases under review [7].” He will also consider “behavioral similarities and dissimilarities [7].”      
Some cases are straightforward: The victims may know the perpetrator or hard evidence may connect and link different crimes to form a series. For the past two decades, the buzzword has been DNA analysis, but before the mass adaptation of DNA science, forensic firearm laboratories and large databases of fingerprints were the primary methods of linking crimes to the same culprit.
The theoretical foundation of linkage analysis relies on the offender consistency hypothesis and the inter-perpetrator behavior variation hypothesis, both of which have found support among several scientific studies that have used a variety of methodologies and data. The offender consistency hypothesis states that the same offender will act with some consistency within same crime types e.g. within robbery, murder, rape; whereas, the latter hypothesis maintains that different criminals behave differently. Case linkage difficulties may be exacerbated by a long list of variables including a lack of hard evidence and by dead victims. A surviving victim may be able to describe an offender’s behavior, which may consist of peculiarities. The context in which a behavior occurs also needs to be taken into consideration as situational factors can affect crime scene dynamics; for example, a victim may fight back causing the offender to use a degree of violence which he or she did not exhibit in previous crimes. A serial offender may exhibit a signature, which is sometimes also called personation. It is regarded as a ritualized action based on needs or compulsions, but it does not facilitate a crime or help to conceal it. It is an unconscious element that is acted out. If a signature can be detected it can assist the analyst linking crimes together. The signature can be a physical element or can be expressed via input from the offender, for example, highly abusive language i.e. a verbal signature. While the signature, according to major works on criminology, does not aid the offender in carrying out the crime, the MO, on the other hand, does exactly that. According to FBI’s Crime Classification Manual: A Standard System for Investigating and Classifying Violent Crimes, first published in 1992, the MO can be defined as: “Actions taken by an offender during the perpetration of a crime in order to perpetrate that crime form the MO. MO is a learned set of behaviors that the offender develops and sticks with it because it works, but it is dynamic and malleable. In any criminal career, no matter what the circumstances, the MO will evolve with the criminal. Every criminal makes mistakes, but most learn from them and try to get better with time …[8].”
By carefully considering the established facts of the two cases, it is clear that a number of similarities exist. First, we will categorize and list these similarities. Next, we will consider several important dissimilarities, which, contrary, may suggest that the two murders were not committed by the same man. In addition to the inherent difficulties and uncertainties in case linkage, our ability to compare and evaluate is also weakened by a lack of access to autopsy reports, forensic tests, and other information.

Victimology 

The victims, Maria Ngui and Monika Pawlak, share numerous similarities: Both were prostitutes, easy to persuade, immigrants, and the victims had low social contact. The major difference is race: Pawlak a Caucasian whereas Rosa an African. Some killers select their victims based on availability rather than race or even gender, although killers are statistically more likely to target their own race. If Sunny, the aforementioned sex worker, actually encountered the killer, which the evidence indicates, it suggests that race was not important to the killer as she is a Caucasian.
In 2011, the U.S. Department of Justice released their statistics for “Homicide Trends in the United States” from 1980 to 2008 [9]. Within this time frame, the average age of homicide victims was consistently higher than the age of offenders.

Average age of homicide victims and offenders, 1980-2008.

For US serial killers, the trend is similar with a reported average age of 27.5 years for serial killers and 33.78 for victims. For the cases under review in this article, the offender(s) appears to have been older than the victims. Pawlak was 24 years old and the suspect was 35-45 years old. Rosa was 48 while the suspect was 50-55. For the purpose of this analysis, the offender’s age progression continuity from 2010 to 2017 is consistent with the one offender hypothesis.

Dismemberment

Criminal dismemberment is rare and this fact alone raises the probability considerably that one killer committed both killings. For instance, between 1959 and 1984 the Institute of Legal Medicine in Hamburg handled only 27 cases of criminal dismemberment for an average frequency of about 1:500 or 0.2%. In a follow up study from 2019 by Wilke-Schalhorst et al, the overall prevalence was shown to have dropped to an average of less than one case per year. Specifically, from 1959 to 2016 the coroners in Hamburg had only worked on 51 cases of dismemberment. A scrutiny of the 51 cases revealed that “in most cases, the perpetrators were middle-aged men from the close social environment, who had no psychiatric primary illnesses, no experience in the medical sector, and had not worked professionally as a butcher.” Studies examining the background of those who have dismembered their victims have shown mixed results in regard to whether or not they possess relevant anatomical knowledge. Contrary to the aforementioned study, the data collected over a 30-year period by Lundström et al indicated that in over 50% of the cases involving dismemberment “the perpetrator‘s occupation was associated with application of anatomical knowledge, for example, a butcher, physician, veterinary assistant, or hunter.” Due to dismemberment being a rare phenomenon most of the studies had to rely on small sample sizes explaining the conflicting results.
While dismemberment is rare, we also need to consider the likelihood that the dissected body parts would be put into garbage bags. Although no data could be found in this regard, the figure is clearly very low. Another statistical aspect to consider is that both victims were prostitutes. Although the two cases, we are examining, do not amount to a serial killing, which is defined as at least three victims with a cooling period in-between, it is relevant to consider a 2011 study by Kenna Quinet who examined serial killer trends and case characteristics from 1970 to 2009. She found that a total of 32% of U.S. serial killers had targeted prostitutes. In the aforementioned study from Wilke-Schalhorst et al, an examination of the victims’ backgrounds (the profession of 43 out of 51 was known) yielded a figure of 16% for victims who had been a prostitute.
With the above statistics in mind, it is exceedingly likely that only one offender is operating due to the rarity of the elements present in both cases.
When the killer severed the limbs, ears, and other parts of Maria Ngui it was expertly done and it appeared primarily to have been fantasy driven for reasons outlined earlier. Contrary, Pawlak’s killer displayed limited professionalism when he severed her arms, legs, and head from her torso. In the Hannover instance, the offender appears to have dismembered the body, first, and then put it in a freezer or other cooling place. By lowering the temperature of the body, the killer would have avoided the negative effects associated with a decomposing corpse in case that he could not transport the body to a dumping site soon after. He may even have been of the impression that freezing the body would destroy DNA and other evidence. No information has been released stating that the killer mutilated Pawlak. These points suggest that the Hannover killer dismembered her for defensive reasons as opposed to the fantasy driven dismemberment of Maria Ngui. The conclusion is weakened by the missing body parts that produce an incomplete dismemberment pattern; he could have buried them, went undetected by searchers of the Ihne, or kept by the killer for his own gratification.
The most potent piece of evidence pointing toward the two offender hypothesis is, without question, that the Hamburg killer displayed clear anatomical knowledge while the Hannover killer did not. However, we need to take the situational factors into consideration. The police have surmised that the killer had access to cocaine given that the victim took it in close proximity to her death. They have also deduced that, based on the poor quality of the plastic bags, the killer acted on impulse. If their conclusions are accurate, it raises the probability that the killer was under the influence of cocaine and other psychotropic compounds. If the offender was intoxicated to the point where his physical and mental control was markedly diminished, it may explain why he botched the dismemberment even if he had relevant anatomical knowledge. Driving while intoxicated can produce similar behavioral changes such as a lack of coordination.

Geography

It is remarkable that the witness, mentioned earlier, recalled seeing a man 15 months prior on January 1 at 12:10 p.m., pulling sledges with a blue garbage bag on top of each of them. The witnesses even gave the police a reasonably detailed description of the suspect. If the event had been trauma based there would have been a justification. However, there was no trauma associated with the event or any conceivable reason as to why the witness should have encoded the event into her memory to such an extent. We can speculate that he was looking suspicious or acting strange to the point that she encoded the event into her long term memory; even though, the city was covered with snow for weeks, and people with sledges were presumably a common observance.
Memory is a complex constructive process that is susceptible to distortion, especially with the passage of time because memories, for the most part, become less detailed and specific and tend to become more broad and generalized. Besides time, multiple influences can affect memory. Memory is more like an impression than a video recorder. The unreliability is best illustrated by numerous judicial cases in which a witness or more were certain of their identification of an accused, leading to a conviction, but only later to be overturned by solid, forensic evidence [10]. With these abbreviated facts about memory in mind, it follows that the testimony of the witness should be regarded with acute skepticism and a much broader time frame is likely. If she had seen him at 12:10 p.m. the killer had limited time to approach the victim, entice her to follow him, murder and dismember her, and freeze the body.
According to a weather station in Hannover, the temperature on Friday, January 1, 2010, oscillated between -1 °C and -2 °C, making it unlikely for the killer to have frozen the body outside in view of the very narrow time frame he was operating within [11].

Figure B outlines the major locations in the case. At number 1, the witness saw the man with the sledges. Specifically, she saw him on the pedestrian bridge between Ihme Passage and Peter-Fechter-Ufer Street. She said, he walked in the direction of Schwarzer Bär, marked with a 2. The body parts were found underneath the Legion Bridge, at 3. It would have taken approximately 15 minutes for the man to walk from the bridge to the dumping site.

There are several unanswered questions which have yet to be addressed. First, it is a mystery why the killer transported the body parts at noon /daylight (assuming the witness is reasonably accurate); why not wait until the streets were deserted late at night?    
When the killer placed the two garbage bags underneath the bridge, he did not throw them into the water (which would have been to his advantage), but instead he arranged them, right next to the Ihme river.   
Given the time, location, and overall circumstances there is little doubt that the man observed by the witness is involved in the killing. In addition, the soil evidence, which led to the police scrutinizing the inhabitants of the high rise buildings, came from the vicinity of the pedestrian bridge on which the suspect was observed. If we contemplate the killer’s decision to use sledges as transportation as well as his decision to dump the body under a bridge, which only can be accessed on foot, it is likely that he was a local man who had well-defined knowledge of the area. Similarly, there is little doubt that the Hamburg killer had extensive knowledge of the city. The shortest route between St. George and Peter-Fechter-Ufer Street is about 159 km or one hour and 47 minutes. An FBI study, which had access to a broad data-set encompassing 92 serial killers and a total of 480 victims, showed that serial killers, most of the time, adopt a hunting ground with which they are familiar [12]. There are rare exceptions one of whom was Ted Bundy who spread out his murders across several US states. The study, which utilized data from 1960 to 2006, shows that serial killers commit 72.3% of their murders intrastate and 26.9% interstate. It is indicated that if it is one killer operating, he has lived or spent a significant amount of time in both cities.

MO and Signature

Because the victims are deceased our understanding of the MO in either case is limited to isolated events, such as the handling of the bodies. In the Hannover instance there is a gab from the time the victim went toward the city and until she was discovered in garbage bags under the Legion Bridge. We may speculate that the killer enticed the victim with cocaine or hired her for sexual services, possibly near Mehlstrasse. This street is located only 1.6 km from the spot the suspect was seen. In Hamburg, the killer was similarly not bothered by operating near or at the city center. No similarity is though noted in the time and date at which Pawlak and Ngui were approached (after 2 a.m. on a Friday and at about 2 p.m. on a Tuesday respectively).
Determining a signature, if any, is not easy as our access to information is restricted, but the consistent placement of body parts in or at water may have fulfilled a bizarre unconscious need of the offender. However, some researchers would probably argue that such a signature is too generalized and can thus not be regarded as one. 
The autopsy report of Maria Ngui lists her cause of death as unknown; very little information regarding the method used to kill Monika Pawlak has been released, except that the killer stabbed her to death. Ngui may have been strangled or even dismembered while being alive. If she had been stabbed such would have been obvious during the autopsy.   

Profiling

Upon realizing that the clues led to dead ends, the police formulated a profile of the killer in conjunction with psychologists. Based on the evidence, the police reached the following conclusions about Monika Pawlak’s killer [13]. As for their methods used to extrapolate the points, the police had little to say.

►Lived (at least at that time) alone.
►Has access to drugs (cocaine).
►Special access to the Legion Bridge.
►Pragmatic thinking, psychologically stable.
►Craft-oriented (close to metalwork).
►Physically able to carry heavy loads.
►Has combined apartment/workshop and/or gazebo.
► There are dogs and cats nearby. 

Conclusion

Statistically, it is more likely that one offender killed Maria Ngui and Monika Pawlak; yet, it is difficult making firm statement due to a lack of information and the inconsistencies covered earlier.

About the writer: Søren Korsgaard, author of America’s Jack the Ripper: The Crimes and Psychology of the Zodiac Killer, is the editor of www.crimeandpower.com and webmaster of www.paulcraigroberts.org. Support Søren’s work by donating Bitcoin: 19Z22vsdaKJX4gy8GDy6J8QU1ZZ9EvSoEo   

References

1. “Erste Hinweise Fuhr der Stückel-Mörder ein weißes Auto?”  https://www.mopo.de/hamburg/polizei/erste-hinweise-fuhr-der-stueckel-moerder-ein-weisses-auto–28155214
2.  “’Mordkommission Rose’ erhofft sich neue Zeugenhinweise https://www.pd-h.polizei-nds.de/fahndung/zeugenaufruf/mordkommission-rose-erhofft-sich-neue-zeugenhinweise-110942.html
3. “3000 Euro Belohnung im Fall Monika P.” www.sn-online.de/Aus-der-Region/Stadt-Hannover/Uebersicht/3000-Euro-Belohnung-im-Fall-Monika-P
4.  www.haz.de/Hannover/Aus-der-Stadt/Uebersicht/Die-schwierige-Spurensuche-im-Fall-Monika-P 
5. ”Polizei bittet männliche Bewohner des Ihmezentrums zum Speicheltest”  http://www.haz.de/Hannover/Aus-der-Stadt/Uebersicht/Polizei-bittet-maennliche-Bewohner-des-Ihmezentrums-zum-Speicheltest
6) “Polizei Hannover hat eine Spur im Fall Monika P“ http://www.sn-online.de/Aus-der-Region/Stadt-Hannover/Uebersicht/Polizei-Hannover-hat-eine-Spur-im-Fall-Monika-P
7) Turvey, B.E. & Freeman, J. (2016). Applied Case Linkage Analysis. 10.1016/B978-0-12-800607-8.00016-1.
8. Crime Classification Manual: A Standard System for Investigating and Classifying Violent Crimes. John E. Douglas, Robert K. Ressler (1992 Lexington Books).
9. Alexia Cooper and Erica L. Smith,  Homicide Trends in the United States, 1980-2008 https://www.bjs.gov/content/pub/pdf/htus8008.pdf
10. Lacy JW, Stark CEL. The neuroscience of memory: implications for the courtroom. Nat Rev Neurosci. 2013;14(9):649-658.
11. “January 2010 Weather in Hannover — Graph” https://www.timeanddate.com/weather/germany/hannover/historic?month=1&year=2010
12. Robert J Morton; Jennifer M Tillman; Stephanie J Gaines. “Serial Murder: Pathways for Investigations.” National Center for the Analysis of Violent Crime, U.S. Department of Justice.
13. ”Polizei sucht mit Video nachMörder von Monika P. († 24)” https://www.bild.de/regional/hannover/polizei/sucht-mit-video-nach-moerder-von-monika-42183244.bild.html

Author Since: Apr 09, 2019

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