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2012. The New York Police Department (NYPD) received a call informing them of a possible homicide. The informant described a new friend he had recently met who had a problematic roommate. During a recent phone conversation, the informant asked if his friend was still having problems with his roommate. The friend told the informant that he did not because he had killed him and cut him up into small pieces. He then asked for help disposing of the body.

Fig.1 The two shared an apartment at 3395 Nostrand Avenue in Brooklyn.

The NYPD then contacted the Office of Chief Medical Examiner (OCME) and members of the Forensic Anthropology Unit (FAU) and Medicolegal Investigations responded to assist. Upon entering the scene, human skeletal remains and numerous containers filled with soft tissue were observed in the refrigerator in the apartment, and tools were noted in the adjacent bathroom.

Fig.2 The victim Aleksandr Zilbergleyt.

The postmortem examination took place in two phases. First, the medical examiner performed the autopsy and identified 92.5lb (42kg) of soft tissue that was cut small enough to be put in the pour spouts of 10 1-gallon (4.6-l) bottles of bleach, one bottle of muriatic acid, one bottle of drain cleaner, and one small plastic bag. The FAU then took custody of the case for a full skeletal examination. The inventory of remains revealed a nearly complete skeleton with only some finger and toe elements missing.

Fig.3 One of the bleach containers, and after being cut open from the base showing its contents, and its contents laid out.

Fig.4 The freezer showing the human remains.

Fig.5 Refrigerator showing the human remains and bottles as they were found.

There was a probable victim in this case who was quickly identified via partial fingerprints recovered from the bottles as well as radiographic comparisons of antemortem surgeries of the knee and shoulder. The anthropological profile was consistent with the decedent and a skeletal trauma analysis was performed. There was antemortem trauma observed on several ribs, the left scapula, and the right patella, and extensive perimortem blunt force trauma to the cranium.

Numerous cut marks were observed on most of the joints in the body. The cut marks are consistent with dismemberment via disarticulation around the joints, with cuts on all of the joints between the long bones, the vertebral bodies, the bones of the feet, and some of the bones of the hands. There are cut marks on the hyoid bone, indicating that it was manually separated from the soft tissues of the throat.

Fig.6 The bathroom with tools on the back of the toilet.

Fig.7 The tools laid out.

There are numerous cut marks on the ribs as well as on all of the vertebrae and some cut marks observed on the cranium are also consistent with defleshing. Most of the cut marks observed are V-shaped, indicative of a knife or other beveled instrument; however, the defects, in general, are shallow with minimal bone contact, precluding further evaluation of blade type. Some of the pedal phalanges and all of the costal cartilages were completely transected. Microscopic evaluation of some of these cartilages shows patterned striations which indicate that these areas were impacted with a serrated blade or blade portion.

Upon questioning, the suspect revealed that he and the decedent had gotten into a fight and the decedent was knocked unconscious. He stated that he moved the decedent into the bathtub and tried to use the chemicals to dissolve the body but was unsuccessful. Following that failed attempt, he cut the body into small pieces using only hand tools, so as not to disturb the neighbors, in addition he ran the brain through a meat grinder. The emptied bottles were then used to store the tissue.

Fig.8 Mamontov ran his roommates’ brain through a meat grinder.

Fig.9 General overview of the skeletal elements and schematic representation of the skeleton with approximate location of cut marks represented by light shading.

Fifty-year-old Russian Sergey Mamontov confessed to dismembering his roommate because, he felt, “there was no other way to take care of [the victim],” according to police sources. Mamontov had squabbled about noisiness and partying with his 55-year-old roommate Aleksandr Zilbergleyt, who had been living there for about eight months. A person living in the building reported hearing a loud crashing sound the day Zilbergleyt disappeared. Police found Mamontov watching TV when they arrived at the residence.

Fig.10 Sergey Mamontov being walked from 61st Precinct

Fig.11 Suspected killer, Sergey Mamontov is escorted out of the 61st Precinct in Brooklyn after being questioned for the murder of his roommate at his Sheepshead Bay apartment

Sergey Mamontov was convicted of murder by a panel of jurors who deliberated just 15 minutes before coming to a verdict. He received a 25 years to life sentence. “I’m going to see a shrink now,” said a horrified 62-year-old female juror, “I didn’t sleep all of last night. This is the worst I’ve ever seen in my life.”

The New York Daily News reported that Mamontov’s case horrified jurors and the prosecution, especially when he took the stand and explained in graphic detail how he disposed of Zilbergleyt’s body by cutting it up into thousands of pieces, throwing his fingers into Sheepshead Bay and running his brain through a meat grinder.

Melissa Carvajal, a prosecutor in the case described the crime as so “horrendous, horrific, gruesome” that Zilbergleyt’s family “couldn’t attend the trial because they simply couldn’t hear the details.”

Fig.12 Sergey Mamontov being walked from 61st Precinct. He confessed to chopping up his roommate of six months, Aleksandr Zilbergleyt.

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