Forensic: May 2009 Archives

Forensic DNA Evidence

Recent advancements in DNA Technology are enabling law enforcement officers to solve cases previously thought to be unsolvable.  Today, law enforcement with a knowledge of how to identify, preserve and collect DNA evidence properly can solve cases in ways previously only seen on TV.  Much the way Trekkies envision a futuristic world of beaming molecules from one surface to another - law enforcement envisions the use of DNA evidence solving crimes faster, more reliably and more frequently than heretofore methods of fingerprinting, eye witness and the old fashioned "gum-shoe" work ethic of eras gone by.  

Because of the uniqueness of each person's DNA, evidence collected at a crime scene can either link a suspect to a crime or eliminate a suspect.  Further, whether blood, saliva or skins cells are collected - a person's DNA is the same throughout.  DNA evidence can also identify a victim or suspect through samples obtained from relatives even when no body can be found.  Crimes scenes can be compared across a State or Country and the same perpetrator identified if his/her DNA is present.

Forensically valuable DNA samples can be found on evidence that is decades old.  However, several factors can degrade the viability of the sample including but not limited to heat, sunlight, moisture, bacteria or mold.  DNA is found is blood, semen, skin cells, tissue, organs, muscle, brain cells, bone, teeth, hair, saliva, mucus, perspiration, fingernails, urine and feces - although most labs are loath to be testing feces looking for viable DNA samples and some of the private labs have discontinued offering such services. 

Creative crime scene investigators can collect DNA evidence from non-traditional sources, such as saliva on cigarette butts or soda cans, sweat on baseball bats or a similar weapon, sweat inside a hat, bandanna or mask discarded at a crime scene, bite mark's containing saliva from the perpetrator, scrapings from underneath a fingernail (this we have all seen on TV shows like Law & Order or CSI).  Today's crime scene detective has to visualize the crime and discern where and when DNA samples were transferred during the commission of a crime from perpetrator to victim; from perpetrator to scene surface etc.,   DNA profiles of those involved in the crime scene investigation (other than the perpetrator and/or victim) should be provided to the lab in order to eliminate possible contamination to evidence.

DNA collectors, laboratory personnel, lawyers and investigators should work as a cohesive unit to determine the most probative pieces of evidence and to establish priorities.  Most state DNA laboratories are backlogged with evidence yet to be analyzed; however, there are many accredited and reliable private DNA laboratories that can be utilized in DNA detection and profiling.

Since biological material (DNA evidence) may contain hazardous pathogens such as HIV or Hepatitis B or the most recent H1B1 flu, care must be taken when collecting and/or handling samples.  Given the nature of DNA evidence, officers should always contact a local DNA expert for answers about evidence collection.  
  
Every State in the Nation has or is implementing a DNA index of individuals convicted of certain crimes - usually felonies (BARRMS + K - thanks to my college Criminal Justice professor).  Upon conviction, the DNA sample is analysed and profiled and entered into a DNA Database.  Just as fingerprints found at a crime scene can be run through AFIS (Automated Fingerprint Identification System) in search of a suspect or link to another crime scene, DNA profiles from a crime scene can be entered into CODIS enabling law enforcement officers to identify possible suspects when no suspect or lead existed.   

Having  Properly Accredited Private Laboratories assist authorities on DNA Collection and Analysis

In the New York and New Jersey area alone, over a period of approximately 10 years, had DNA samples been collected and analyzed by authorities more than 30 rapes, robberies, sexual assaults or deaths could have been prevented if laboratories were not backlogged, if DNA was collected and perpetrators identified after the first offense rather than after the 13^th offense.

This report was prepared by Smith Alling Lane in partnership with Washington State University through the support of a grant awarded by the National Institute of Justice, Office of Justice Programs, U.S. Department of Justice (Grant 2002-LT-BX-K 003). Points of view or opinions in this document are those of the authors and do not necessarily represent the official position or policies of the United States Department of Justice

THREE PREVENTABLE RAPES

In mid-May 1998, a woman was raped at a public library in Essex County. One month later, a second woman was raped in a library. DNA samples were taken from both cases and loaded into the DNA database, where it was discovered that the two rapes were linked. Importantly, in matching these cases to each other, DNA also excluded two men being held by police as possible suspects.

In late June of 1998, a child was abducted and raped. A DNA sample was collected and sent to a private laboratory for testing, and the victim provided a description of the attacker to police.

The police eventually identified a suspect, and DNA testing subsequently tied him to the child attack. After the sample was loaded into the state database, it was discovered that the same offender was the library rapist. Additionally, the same DNA profile was eventually matched to an October 1999 rape in New York City.

The offender had a prior felony arrest on a weapons possession charge. The charge was later reduced to a misdemeanor crime to which the offender pled guilty. If a DNA sample had been required of felony charges that result in misdemeanor convictions, the perpetrator couldhave been identified after the first rape,thereby preventing the following three rapes.

SEVEN PREVENTABLE ROBBERIES, FIVE PREVENTABLE RAPES

In October of 2002, the first in a series of ten robberies began. The incidents included seven aggravated sexual assaults, spanned four months and included victims in at least nine different New Jersey cities.

A person known to the police became a strong suspect in the first offense, and a DNA sample was collected from him four days later. A DNA match was finally made in January of 2003 to the third offense, but only after a unit commander requested expedited testing of the evidence.

The offender in question was convicted in the 1980's on federal felony robberies charges, and was released from a federal prison in 1999. Unfortunately, the federal government did not begin requiring DNA from felony robbery convictions until 2000. Moreover, law enforcement had custody of all the DNA information that they needed to arrest this offender within only a few weeks of the first offense. The omission of his DNA from the federalDNA database, along with the backlog delay in processing DNA evidence, allowed the offender to remain on the streets. With stronger federal statutes and shorter DNA testing delays, the perpetrator could have been identified after the third attack, thereby preventing

the subsequent seven robberies and five rapes.

FOUR PREVENTABLE RAPES

Between April of 2002 and May of 2003, five women were raped in the Trenton area. DNA testing linked all five offenses to the same unknown perpetrator. After police released a composite sketch of the suspect in 2003, nearly 75 tips were called in identifying the same person. In June 2003, U.S. Marshals eventually arrested the suspect in Pennsylvania on a parole violation warrant that was issued in July of 2002. Trenton Police obtained a DNA sample from the suspect through a court order, and thanks to expedited testing at the state laboratory the man was linked to the crimes within a few days. The charges on 16 counts

involving five victims are pending as the suspect awaits extradition to New Jersey from Pennsylvania.

The suspect's criminal record included two felony convictions for theft and forgery related offenses in New Jersey, and nine felony convictions for theft, forgery, and receiving stolen property in Pennsylvania. If the suspect had been required to give a DNA sample for any of these crimes in either state, he could have been identified after the first assault, thereby preventing the subsequent four rapes.

THIRTEEN PREVENTABLE RAPES

In August of 1993 a young woman was raped in the Bronx in what was to be the first of up to 51 rapes attributed to the same offender over a five-year period. The perpetrator was dubbed the "Bronx Rapist" by the media. A person known to the police became a suspect when he was identified in a transaction involving a victim's jewelry at a pawnshop. He was arrested and subsequent DNA testing linked him to several of the rapes. He has been convicted on fourteen counts of rape in the Bronx, six counts of sexual abuse, nineteen counts of robbery, and two counts of criminal possession of a weapon.He has been sentenced to two life sentences.

This offender had a prior conviction in 1989 for felony robbery and assault, for which he received a seven-year sentence. If the State of New York had begun requiring DNA from all convicted felons in 1990 this offender would have been on the DNA database prior to the first rape in 1993, and at least thirteen rapes could have been prevented. Moreover, when New York's database was established in 1994, an inclusion of all convicted felons and retroactive application to persons previously convicted but still under supervision would have captured this offender's DNA sample much earlier in the investigation.

TWO PREVENTABLE SEXUAL ASSAULTS, ONE PREVENTABLE DEATH

From 1991 to 1999, three young women were murdered in New York City and four others were raped. The youngest victim was 13, and several of the crimes were noted for their brutality. During the course of the investigation, police identified a man who had just been released from jail for a sex crime in the same area in which a victim had been raped. He had been seen in the neighborhood just before and after the rape, and was picked out of a lineup. The man was jailed for four months, but DNA testing subsequently eliminated the man as a suspect.

Another person known to the police became a suspect in these crimes in 1999 and was placed under surveillance by police. He was eventually arrested on petty theft charges and DNA testing later linked him to evidence from the crimes. This person had been released from custody pending the DNA testing, and was arrested again in Miami after the DNA match was made. He was found with a young woman who may have been his next victim. This offender was found guilty on twenty-two counts, and sentenced to 400 years in prison.

This offender had been convicted of felony robbery in 1992 at a time when New York did not collect DNA samples from criminals convicted of felony robbery. Moreover, if a 1996 expansion of the database to include robbery convictions had been applied retroactively, he could have been required to provide a DNA sample at this point. The sample would have been linked to one of the previous crimes, thereby preventing at least two sexual assaults against juveniles and one death. It is also worth noting that a sooner DNA match would have prevented an innocent man from spending four months in prison.

SEVEN PREVENTABLE RAPES AND ROBBERIES

In 2001 it was revealed that New York City had between 14,000 and 16,000 unanalyzed rape kits that were sitting in a storage rooms. Through a focused backlog reduction program, the City has been analyzing the rape kits and loading them into the state DNA database system.  In 2002, two unsolved rapes that were part of the backlog reduction project were connected to the same offender. The offender's criminal history included five prior arrests which resulted in

two separate felony convictions - in 1991 for robbery and sexual abuse, and in 1997 for armed robbery. Although New York was not collecting DNA from robbery convictions in 1997, a 2000 law expanded the database to include robbery and included offenders who were still incarcerated for previous convictions. Upon release in 2001, the offender in question was required to give a DNA sample for the database.

This offender was arrested in December 2001 for a series of rapes and robberies (seven separate incidents). If the 1996 rape kits had been tested sooner, this person would have been linked to these assaults in 2001 prior to his release, thereby preventing the subsequent 7 attacks occurring after his release.