FILE - In this Aug. 31, 1999 file photo, convicted murderer Jerry "Animal" McFadden, left, looks at his attorney Vernard Solomon, right, while Upshur County Sheriff R.D. "Buck" Cross, center, follows him out of the Upshur County Courtroom after his execution date was set in Gilmer, Texas. McFadden, who was executed by the state of Texas in 1999 has been identified via DNA as the person who killed a 20-year-old woman in Portland, Ore., nearly 40 years ago. Anna Marie Hlavka was slain in an apartment on July 24, 1979. Authorities said Thursday, Jan. 31, 2019, her killer, McFadden, was identified using the same technology that led to an arrest last year in California in the "Golden State Killer" case. (Kevin Green/The News-Journal via AP, File)
camera (The Associated Press) FILE - In this Aug. 31, 1999 file photo, convicted murderer Jerry "Animal" McFadden, left, looks at his attorney Vernard Solomon, right, while Upshur County Sheriff R.D. "Buck" Cross, center, follows him out of the Upshur County Courtroom after his execution date was set in Gilmer, Texas. McFadden, who was executed by the state of Texas in 1999 has been identified via DNA as the person who killed a 20-year-old woman in Portland, Ore., nearly 40 years ago. Anna Marie Hlavka was slain in an apartment on July 24, 1979. Authorities said Thursday, Jan. 31, 2019, her killer, McFadden, was identified using the same technology that led to an arrest last year in California in the "Golden State Killer" case. (Kevin Green/The News-Journal via AP, File)

A convicted murderer called the "Animal," who was executed by the state of Texas in 1999 has been identified by DNA as the person who killed a young woman in Portland, Oregon, nearly 40 years ago.

Anna Marie Hlavka, 20, was killed in an apartment on July 24, 1979. Authorities said Thursday her killer, Jerry McFadden, was identified using the same technology that led to an arrest last year in California in the "Golden State Killer" case.

Hlavka was sexually assaulted and strangled with an electric cord. The Portland Police Bureau said at a news conference retired detectives submitted evidence to the state crime lab in 2009 for forensic testing.

Authorities said that evidence eventually showed McFaddden, who was executed in Texas for the rape and killing of an 18-year-old high school cheerleader, was Hlavka's killer.

The 51-year-old McFadden was a notorious criminal in Texas. He was sentenced to death for a daylong murder rampage in 1986 that took the life of the cheerleader as well as two other people.

Authorities said it took years of research and detective work to determine that McFadden killed Hlavka.

Portland police said an "unknown male DNA profile" was found in 2011 in evidence collected from the scene of the 1979 slaying. The profile was deemed especially good considering how much time had passed.

From 2012 to 2016, detectives collected and submitted eight subjects' DNA profiles in an attempt to identify the killer, but authorities said all came back negative.

Last May detectives researched forensic genealogy using unidentified DNA profiles from homicides scenes, the technology used to bring about the May 2018 arrest of the suspect in the "Golden State Killer" case.

Detectives contacted Parabon NanoLabs and the Oregon State Police Crime Lab and it was determined that the evidence from the Portland cold case was a good candidate for that technology.

Scientists were able to map three of the four familial lines of the Portland killer and identified him as McFadden.

Detectives travelled to Texas to interview McFadden's relatives and obtain further DNA samples.