La Porte County Sheriff's Office identifies Carl David Phillips as killer in 1981 murder of Juanita Boyd

The La Porte County Sheriff's Office announced at a news conference Tuesday morning they have identified the killer in the 1981 cold case murder of Juanita Boyd.

Juanita Boyd was 31 years old when she first went missing. Police said she was last on Feb. 21, 1981 at a bar in La Porte, Indiana. Six days later her car was found in a rural area with her body inside.

Police investigated Boyd's boyfriend at the time as a suspect, but no charges were ever pursued. Evidence collected from the crime scene when her body was found included body fluids in her undergarments.

Tuesday, police said years of work by detectives and advances in technology allowed them to test those fluids for DNA and then, with the help of Parabon, a genetic genealogy lab, and the Indiana State Police Lowell lab, they were able to develop a family tree of the suspect which eventually led them to an ID.

Now, more than 45 years after her murder, police said they identified Carld David Phillips as Boyd's killer.

Police said they relied on a combination of physical evidence and circumstantial evidence to make the identification. They also said the DNA evidence developed in the case definitively ruled out her boyfriend at the time as a suspect.

Police said along with the DNA, Phillips had access and familiarity with the rural area where her body was found, and had no relatives in the area with whom the DNA evidence could be confused.

Police said Phillips died in September 2017. They said they brought their case to the La Porte County prosecutor's office and presented it, and prosecutors said if Phillips were still alive today they would have gone on to file murder charges against them.

"I will forever be indebted to the tireless work of every investigator who has worked on this case from 1981 to present," said Captain Andrew Hynek, the lead investigator on the case.

Hynek said because the evidence from the crime scene had been so painstakingly preserved, detectives working on the cold case had an advantage when using the new DNA technology available today.

The La Porte County Sheriff's Office first announced they were reopening the investigation into Boyd's murder using new DNA technology in 2013. Police said in the 13 years since, they have continued to work the first family tree developed in 2013 in order to identify Phillips as the killer.