Sacramento County Sheriff’s Department using new DNA technology for cold case – ABC10

Alexa Renee, KXTV 5:43 PM. PDT August 08, 2017

Investigators say Robin Brooks found dead 37 years ago was sexually assaulted prior to being stabbed to death in her apartment. (Photo: Sacramento County Sheriff's Department)

The Sacramento County Sheriff's Department is taking a crack at a cold case using an advanced DNA technology.

On April 24, 1980, Robin Gisela Brooks, was found stabbed to death in the bedroom of her Rosemont apartment. The 20-year-old had been sexually assaulted prior to her death and investigators found DNA evidence of the suspect at the crime scene but have been unable to identify the killer.

Brooks was scheduled to work at Donut Time on Kiefer Boulevard on the day she was found dead, but never show up for her shift. That's when coworkers came looking for Brooks and made the tragic discovery. Brooks family has a $10,000 reward for information leading to the arrest and conviction of the person responsible for her murder.

Her family may get closer to getting answers because of the sheriff's department new efforts in finding the suspect. The department has a full DNA profile of the suspect but no matches have come up on any federal or state DNA database.

Sacramento County investigators are hoping DNAphenotypingcould paint a picture of who killed Brooks. The DNA service cost the department $4,000 and is charged per case, it's not a flat rate fee. It's the first time the sheriff's department has used DNA phenotypingto try and solve a case.

What is DNA phenotyping?

Phenotyping can also help identify relatives of a person through DNA connections.

The testing cannot determine factors such as age, weight and facial hair since those details are not available in a person's genetic code. Parabonpredicts a person at 25-years-old by default. Forensic artists would have to adjust age, facial hair and weight based on description information provided by police or eye witnesses.

DNA phenotyping helps illustrate what a person may look like when there are no leads on identification or when a DNA profile doesn't match anything in a database. The tool is especially helpful in case like the Brooks murder, where there were no eyewitnesses to the crime to describe a suspect, but traces of DNA were left behind.

The technology was created fordefense, security, justice, and intelligence communities and has been used by numerous agencies to help generate leads. Private citizens have used Snapshot to find ancestry information.

Has DNA phenotyping helped solve cases?

Phenotyping can be a great tool for eliminating suspects and sparking leads.

Police had previously believed the suspect was a Latino male because Bouzigard was last seen with a group of Latino men. However, the Parabonanalysis found the suspect to be a white male.

Parabon led the Rockingham County Sheriff's Office to Jose Alvarez Jr., the brother of couple's daughter's boyfriend at the time of the murder. He was arrested in Aug. 2015 and later pled guilty to two both murders. In July of 2016, he was sentenced to two consecutive life sentences without the possibility of parole.

Phenotyping can also help with unidentified remains when there is no visual on what the person may have looked like.

What are the issues with DNAphenotyping?

Phenotypingrelies on identifying using physical appearance, which is a method that can run into some problems. Parabontechnology cannot positively create a photo ID of a person, it can only help create a visual when there are no other leads.

Also, a person can look like a sibling or relative, or even another completely unrelated person. There's no science available that can confirm a person's DNA through face structure.

The only way to identify someone using DNA phenotypingis if a person of interest is tested for DNA and it comes back as a match with the sample used to create the Parabonsketch. This means, there'd have to be a tip leading to that person. Unfortunately, the actual suspect may not look like the sketch and misleading tips may come in.

Another issue the ACLU touches on is social and racial profiling. When a sketch is that of a person of color it can fuel "existing societal prejudices to further increase the risks to innocent people". Also, police officers with less sophisticated science tools may rely too heavily on the images and pressure DNA tests from innocent people.

Phenotypingshould be used as more of a tool to narrow down or eliminate suspects, rather than as a point of probable cause to "create" a suspect.

In cold cases such as the killing of Brooks, phenotypingcan help jog memories of someone who may have seen something or knows anything about the suspect, since there is nothing else to go on to solve the case but the DNA profile of the suspect.

Below are the Snapshot DNA phenotyping results for the suspect in the Brooks case. Note physical appearance of subject may have changed over the years.

Snapshot prediction of suspect in 1980 murder of Rosemont woman, Robin Grisela Brooks. (Photo: Parabons NanoLabs Inc.)

Snapshot prediction of suspect in 1980 murder of Rosemont woman, Robin Grisela Brooks. (Photo: Parabons NanoLabs Inc.)

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Sacramento County Sheriff's Department using new DNA technology for cold case - ABC10