After almost 30 years, the skin cells found under Tolila Brown’s fingernails finally led the police to the man they think killed her. On Nov. 2, 1981, Brown, who was then 36 years old, was found dead in a shack on an abandoned lot along Minford Place in the Morrisania section of the Bronx. She was found with a scarf around her neck, which was used to strangle her. The scarf had been tightened with a chisel.
Close to 95 % of cases supported by DNA evidence end in a guilty verdict, experts say. (AP)
A yearlong investigation failed to unearth any leads on the case, and it was abandoned. Nearly three decades later, however, samples of skin cells found under the victim’s fingernails were subjected to DNA testing, and a suspect was identified: 56-year old Jesus Aguilera. On Wednesday, the Bronx State Supreme Court unsealed an indictment against him with a single count for murder in the second degree.
Police Sgt. Carlos Nieves of the New York Police Department told the Bronx Ink that Aguilera is already serving two sentences of 20 years to life for the murders of Guillermo Graniella, 30, and Josephina Cepada, 24, committed in August and September 1981, respectively. Graniella’s murder took place on Park Avenue in the Bronx, Cepada’s on State Street in Manhattan. “Similar to Moore,” Nieves noted, “both Graniella and Cepada died from strangulation.”
The new technology provides the strongest evidence in many prosecutions, experts say.
“For juries, it is definitely the most important piece of the puzzle; DNA is considered the gold standard of evidence,” said Lawrence Kobilinsky, a professor of forensic sciences and chairman of the Department of Sciences at John Jay College of Criminal Justice. Kobilinsky added that close to 95 percent of the cases that involve DNA evidence end with a guilty verdict.
DNA testing was first used in criminal cases in the 1990s, and “it was a revolution for investigations because it is much more stable than proteins or carbohydrates; those degraded very fast,” Kobilinsky went on. Since then, “progress in testing technologies, in computer technologies and the expansion of the DNA database have made it extremely reliable and sensitive.” Kobilinsky, who is also the co-author of the book “DNA: Forensic and Legal Applications,” explained that “until four or five years ago, skin cells could only be analyzed if at least 15 cells were collected. But now, a new technique called ‘low copy number’ allows analysts to get information from smaller samples.”
Located in the nucleus of the cell, DNA can be found in samples from blood, semen, bones, saliva, hair, nails and skin cells. As of January of this year, the National DNA Index (NDIS) contains more than 8 million profiles, from convicted offenders to unidentified human remains. The U.S. Department of Justice says that since the NDIS was created in 1989, it “added value to the investigative process” in 103,400 cases. In the state of New York, the 330,390 profiles have helped solve 9,164 investigations.
Still, although accuracy and sensitivity has improved in the past decade, DNA testing is not automatically used in criminal cases. The decision is made on a case-by-case basis by the presiding prosecutor or detective. “New York City has a team of over 180 analysts working on DNA samples from sexual abuse and homicide cases,” Kobilinsky said. “Most jurisdictions don’t have this kind of human resources but still, it isn’t enough to have every criminal investigation include a DNA test.”
Kobilinsky estimates that for a simple case, the cost of analyzing a DNA sample is under $400. “In private laboratories, the cost can be higher, but in publicly funded forensic crime labs, it remains rather cheap,” he said. Cheap in money, maybe, but not in time: According to a survey issued in 2005 by the National Bureau of Justice Statistics, DNA analyses are “10 times more time consuming and complex than other forensic services.”
There are more reasons why DNA should not be looked at as a definitive end to crime investigations, experts said.
“DNA evidence is like any other evidence,” said David H. Kaye, a law professor at Penn State. “Once you’ve collected it and matched it with a person, it doesn’t answer every question. You have to find out how and when those DNA samples got there. DNA associates a person with an event, but the explanation for that association could prove him/her innocent.”
Jesus Aguilera pleaded not guilty in this third prosecution, even though he confessed to his two prior convictions, according to Rachel Singer, director of DNA prosecution and the assistant district attorney in Aguilera’s trial.
For this new homicide charge, Aguilera faces up to 25 years behind the bars.