DENVER (KDVR) — Families have finally gotten answers in four separate murders that happened more than 40 years ago across the Denver metro area.

Joe Michael Ervin has been identified as the suspect in the stabbing murders that occurred between 1978 and 1981.

Ervin died by suicide in 1981, according to authorities. He died after an Aurora officer, Debra Corr, stopped him for a traffic violation and attempted to arrest him, but he broke out of handcuffs, took Corr’s gun, and then shot and killed her.

There wasn’t DNA testing back then, but police said they used recent genetic genealogy technology to identify relatives in Texas, and that led investigators to exhume Ervin’s body and match the DNA in the cases.

The victims are all women and have been identified as Madeleine Livaudais, Dolores Barajas, Gwendolyn Harris and Antoinette Parks.

Livaudais was stabbed to death in December 1978. Police believe Ervin came to her door, confronted her and forced his way into her home. She was 33.

Then, in August 1980, Barajas was walking to work when police say Ervin attacked her and stabbed her to death.

Barajas had just moved to Denver from El Paso, Texas, a few months prior to her murder. She worked in the cafeteria of the Fairmont Hotel in downtown Denver. She was 53. A photograph of Dolores Barajas was not available at the time of this publication.

A few months later, in December 1980, Harris was found stabbed to death at the intersection of East 47th Avenue and Andrews Drive in Montbello. Police said she frequented the Polo Club Lounge and was last seen there.

In January 1981, Adams County deputies found 17 year-old Parks in a field at 64th and Broadway. She was stabbed to death.

Members of the Denver Police Department and the Adams County Sheriff’s Office were joined by other law enforcement agencies to announce the identity of the suspect in four cold-case murders. Representatives from two of the victims’ families were also in attendance.