Sgt. Vince Brown’s Detective Work Praised After Murder Conviction

La Mesa police are quietly celebrating the detective work of Sgt. Vince Brown, whose dogged pursuit of a cold case led to Wednesday’s conviction of Marc Exter Jernigan in the 1986 slaying of his former girlfriend’s mother.

An El Cajon Superior Court jury convicted Jernigan of first-degree murder in the stabbing death of La Mesa’s June George on Aug. 8, 1986. He faces 26 years to life in prison at sentencing.

“That case could not have been solved without the great work and assistance from the District Attorney’s Office Cold Case Unit and D.A. Investigators,” police Lt. Dan Willis said Wednesday. 

But the primary La Mesa detective responsible for reopening the case and working it was Brown—a member of the force since 1995, Willis said. 

“Sgt. Brown, on his own initiative and while assigned to other investigative responsibilities, began to re-investigate the case back in the late 1990s (1998 or 1999) on his own,” Willis said. 

“The case took years to work, and was eventually turned over to the DA’s Cold Case Unit, where DA investigators worked the case for many years as well.”

Willis said the main break in the case came when DNA came back from blood on items in the victim’s home—and led to suspect Jernigan. 

“The District Attorney’s Office prosecutors,  investigators and … Sgt. Brown did an incredible job to successfully prosecute this case 25 years after the murder,” Willis said. 

“The La Mesa Police Department pursued the investigation of this case periodically throughout the years—always believing that the case could and would, someday, be solved.”

In March 2007, NBC San Diego reported that police asked for DNA samples from Jernigan and several others in 2001. Jernigan’s was the only sample to match DNA found at the crime scene, police told the station.

According to the NBC report, Jernigan had already hired an attorney at the time of his arrest “but acted surprised when they showed up to arrest him.”

The station quoted Brown as saying that Jernigan “inquired why he was being arrested, and he was advised he was being arrested for the murder of June George.”

Willis said La Mesa police are pleased for the George family—“that they will at least come to some peace knowing that the person who tragically murdered her so violently has finally been brought to justice.”

The Jernigan matter isn’t the first cold case solved by La Mesa police, Willis noted in response to an email query.

“One was a child molest case that occurred in 1974 and the suspect was not convicted until 2001—27 years after the crime (the case did not ever get reported until 20 years after the crime),” Willis said. 

Another involved a missing person case in 1995, he said, “where after years of investigating, the suspect was convicted of murdering his girlfriend even though her body has never been found (one of the first no-body murder convictions in San Diego County).”

And a third case in 1992 involved a missing person taken to Compton and slain—and then had his head and hands cut off. 

“The victim’s head and hands were never found.  Two suspects were convicted of murder seven years later.  That case was solved by LMPD even though there was no cause of death, no known murder scene, no murder weapon, no witnesses, no confessions, no DNA, and no physical evidence of any kind,” Willis said.

Willis said one cold-case murder is still under investigation—that of Scott Martinez inside his house on Date Avenue.

“We never forget our victims and will continue to devote resources and do whatever we are able to attempt to bring justice to those who have been victimized,” Willis said.