DENVER – A man who died in prison in 1996 after being convicted of murdering three women also killed four others between 1979 and 1988 and might be responsible for as many as 20 homicides, authorities said.

Vincent Groves, a tall hulking athlete who played on a high school championship basketball team, strangled most of his victims, Denver District Attorney Mitch Morrissey said.

Groves was first convicted of second-degree murder in 1982 for killing Tammy Sue Woodrum, 17, and was released in 1987 on mandatory parole.

In 1990, Groves was sentenced to life in prison for the slaying of Juanita “Becky” Lovato, 19, and 20 years in prison for second-degree murder in the death of Diane Montoya Mancera, 25.

By using DNA from one of those slayings, crime analysts have since linked Groves to the slayings of Emma Jenefor, 25, Joyce Ramey, 23, and Peggy Cuff, 20, who were all strangled in 1979, authorities said. Strong circumstantial evidence also tied Groves to the 1988 killing of Pamela Montgomery, 35, cold-case detective Mylous Yearling said.

“We now know that he killed these four women. That’s really important to the families of the victims. This gives them an answer,” Morrissey said Tuesday.

“They were very surprised. They thought their cases had been forgotten,” Yearling added.

As part of a cold-case project funded with federal grants, Yearling said he was reviewing unsolved homicides when he realized the cases “were more than coincidences” and DNA evidence made the connection.

When Groves was dying in 1996 at age 42, detectives asked him to share the fate of his victims, but he refused, Morrissey said.

“This man destroyed lives. He destroyed families,” Morrissey said. “He was maybe the most prolific serial killer in the state of Colorado. I believe we’ll link him to more.”