Familial DNA searching to find Teardrop Rapist

Alejandra de la Fuente — July 9, 2012 @ 8:31 AM — Comments (0)

LAPD detectives need leads to serial rapist rampant since 1996

The ridiculous number of 35 rapes attributed to the California Teardrop Rapist has the L.A. Police Department detectives pondering the use of a risky form of DNA testing in the hopes of finding this serial sexual predator. They have found the same DNA from 10 of his victims. Only three other things link the Teardrop Rapist to all 35 cases: a distinct way of approaching victims (mode of operation); a general region of his crimes, identified by police’s computer analysis; and similar description as a Latin male aged 40-50.

But one problem differentiates this DNA case from most. The DNA evidence does not match any of the some 9 million existing profiles in the FBI’s Combined DNA Index System (CODIS). DNA has to be matched to that of someone on file for them to know who it is.

LAPD Det. Sharlene Johnson now says they “are looking into DNA familial testing.”

DNA familial testing—better described as familial searching—is not something that we have discussed much, because it has very rarely, and only desperately, been implemented to find perpetrators.

Last year, the LAPD used this method to find and convict Ronnie Franklin Jr. as the previously unidentifiable Grim Sleeper serial killer. Franklin had also left DNA behind at crime scenes that matched no DNA profile on record. He had never committed a crime that would mandate the entry of his DNA profile into the database.

How does familial DNA searching differ from normal DNA database searches?

A normal DNA test generates a genetic profile by 13 genetic markers, with each genetic marker having two alleles (one from the mother and the other from the father). In a normal DNA database search, a DNA profile is generated from a sample of evidence—i.e. semen from a victim’s rape kit—and that profile is compared to a database of profiles belonging to known offenders. The DNA database administrator is looking for an exact match, which can lead to an arrest.

But familial searching is different. Instead of looking for an exact match, familial searching looks for similarities between the DNA profile from the crime’s evidence sample and the DNA of any documented individual, likely narrowed down by a regional filter determined by police investigation.

Thus, familial searching endeavors to find the closest possible match, presuming that will be a family member.

The reason we call it familial searching is because siblings or parents tend of have similarities in their DNA profile. So a match to a similar DNA profile will likely not hit the actual perpetrator, but rather the hope is that it will hit the actual perpetrator’s sibling or parent, who is in the database due to their own criminal activity. It is this hit that can provide a valuable investigative lead into solving a cold case. But it has a reciprocal downside of potentially ensnaring innocent individuals in criminal investigations.

Current status of familial DNA searching

The American Civil Liberties Union of Illinois released a detailed document last year demonstrating their heavy support of an individual’s right to DNA privacy. In the ACLU’s target audience of Illinois, to have one’s DNA placed in the database he must have been convicted of a felony, of violent or nonviolent nature. Some DNA databases are expanding to including those convicted of misdemeanor offenses, felony arrestees (some of whom never actually get convicted), and undocumented immigrants. The ACLU suggests that in the future, applicants for government jobs, benefits, and licenses, and maybe even everyone, with the inclusion of newborns, will also have to submit their DNA profile into the database.

Currently, only California, Virginia, and Colorado approve of the use of familial testing. Maryland has banned it. California Attorney General Kamala Harris has actually increased the budget to double familial searches.

Success and process of familial testing in Grim Sleeper case

Even though Franklin’s DNA was not on file, when ran through a familial DNA test, it showed relative similarity to that of his son’s DNA profile, which had been documented when his son was arrested in 2009 for a weapons charge. Detectives decided to pursue this lead. They posed as servers in a restaurant that they followed Franklin to.

Their method of collecting his saliva from silverware and pizza remnants that eventually enabled them to prove him to be the Grim Sleeper is now being question by courts.

Doubt for the efficacy of familial DNA testing

The ACLU proposes that without restriction, the government can collect DNA left behind by anyone, without volunteering or having lost their right to privacy by being arrested—analogous to the surreptitious methods used by the LAPD to catch Franklin. That idea leads to the classic argument of privacy vs. safety.

They go as far as to suggest that permitting familial DNA testing is taking a step back to a time when eugenics was practiced, as it makes criminal suspects out of mere relatives. It also comes with the cost of a family-only investigation distracting from the possibly unrelated, real perpetrator. Since a disproportionate amount of minorities are on file in the CODIS, familial seearching can start a domino effct that brings suspicion, investigation, and incarceration of even more minorities.

Some would argue that these and other expressed concerns are too constrictive on police departments’ pursual of justice. It suggests that such investigation is burdensome to family, neighbors, and co-workers, but these are the necessary sacrifices of any usual investigation. The question becomes whether communities should be willing to pay the cost of their own time and effort to assist in administration of justice to ensure their own safety.

Relevance to the current Teardrop Rapist search

Even if detectives do find a local resident that, through familial DNA testing, is determined to be a relative of the Teardrop Rapist, will it be constitutional to secretly test relatives of this resident that live in the area?

The ACLU proposes requirements for familial DNA testing that mandate it as a last-ditch effort to find the perpetrator.

The crime also must be of equal nature to murder or rape, and there should be reason to believe that the same perpetrator will strike again. Detectives must have also exhausted all other possible leads. If a partial-familial match is found, additional testing should be done to confirm the link before police start finding other family members.

With only multiple vague sketches, a similar mode of operation, a determined region of where he commits his crimes, and his DNA, the Teardrop Rapist case may just have all of the last-ditch effort attributes that the ACLU requires to sanction familial DNA searching.

Perhaps even adding to the LAPD’s current discouragement is the fact that they convicted a 21-year-old in 1999, thinking he was the serial rapist. But he was later found innocent and exonerated, as the real perpetrator continued his crimes.

The LAPD’s current method of preventing future Teardrop Rapist assaults is passing flyers out in the determined area to increase awareness by making his general face recognizable. The key identifier is his two teardrop tattoos located under his left eye.

Other successes of familial DNA searching

Post-conviction testing of DNA evidence from the crime Daryl Hunt served 18 years in prison for exonerated him. After it did not directly match the DNA of any convict documented in CODIS, it very closely matched that of convict Anthony Dennard Brown. Detectives took this lead. It led them to Brown’s brother Willard.

In the same sneaky fashion that they collected Franklin’s DNA, detectives stole used cigarette butts of Willard’s to test the DNA from his saliva left on them. It completely matched the DNA profiles of the perpetrator found on evidence from the crime scene. Willard pleaded guilty and Hunt was exonerated.


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