On Sept. 14, Carlin Edward Cornett was arrested at his residence in Las Vegas for a National City murder committed back in 1974.
National City Police Sgt. Mark Segal, who served as lead detective on the investigation, expounded on how the cold case dating back nearly 50 years was solved using DNA-related forensic technology.
When Christy Ellen Bryant was stabbed 37 times outside her National City workplace, DNA was not used in investigations but police personnel on scene collected samples of blood belonging to the suspect.
“I’ve worked a handful of cold case homicides and none are this old. The detective work that was done 47 years ago was really well investigated, they polygraphed a lot of people, they used a lot of resources at that time so why was the blood evidence collected in his case? They took blood samples near where the body was found and she was stabbed 37 times so you figure the suspect might have cut himself,” Segal said.
Through blood-typing technology available at the time, the samples revealed they were clearly from someone other than Bryant but not much else.
“They went to great lengths to thoroughly collect evidence, gave at least seven blood samples— they knew it was great evidence but had no idea DNA would come into play. Generally, all homicide evidence is held onto forever in case an appeal comes up, with the forethought that technology does change. People recognize that technology does indeed advance and what is not relevant today might have meaning in the future,” Segal said.
In Bryant’s case, National City police were unable to identify her killer during the initial investigation, the case went cold and the evidence sat in storage for decades.
In 2008, the suspect’s blood, collected at the crime scene, was submitted to the San Diego Sheriff’s Crime Laboratory for further analysis, then entered into the Combined DNA Index System, a Federal Bureau of Investigations system which compiles DNA profiles contributed by federal, state, and local participating forensic laboratories.
Although the system was regularly searched, no hits turned up.
In 2012, NCPD asked the San Diego Sheriff to perform an analysis of the suspect’s blood sample in their laboratory so they could conduct a familial DNA search. NCPD joined forces with the San Diego County District Attorney’s Office Cold Case Homicide Unit to try and solve the case and several searches were performed on the DNA between 2012 and 2016.
A suspect was identified, for which NCPD credits the partnership between agencies, coupled with advances in forensic technology.
“I imagine things will get easier with time but in this case alone, 140 hours were spent by someone trained in genealogy to put together the family trees to come down to Cornett. You need to have dedicated people and that’s where things are really tough. It’s time consuming and requires training. I can’t just one day muddle my way through it, there simply aren’t that many people well versed enough to do that work,” Segal said.
NCPD also credits partnerships between agencies for the arrest.
Members of the National City Police Department, the San Diego County District Attorney’s Office, and the FBI, working in conjunction with the Las Vegas Metropolitan Police Department and the Las Vegas FBI Criminal Apprehension Team all joined forces to arrest Cornett, who will be extradited back to San Diego to face murder charges.
“Everybody was so willing to go above and beyond, and this was such a tragic case. I’m looking at other cold case homicides and looking to do more with them and… It’s early on in genealogy and I don’t want to speculate on where things will go but we’re going to see more of this,” Segal said.