Cops in Pennsylvania say a man already behind bars for committing two homicides could be a serial killer responsible for multiple unsolved slayings that stretch back decades.

Regis Brown, 59, of Fairview, pleaded guilty to brutally murdering his wife, Michelle, 53, and his 35-year-old stepdaughter Tammy Greenawalt inside their Fairview Township home earlier this year. Investigators said he killed the two women in the presence of Browns 14-year-old stepgranddaughter, whom he held captive for several days, police said.

Brown received a life sentence last month after pleading guilty to one count each of first- and third-degree felony murder.

The story mightve ended there, police said, had Brown not decided to keep talking about his past, which they now suspect involves up to a half-dozen other homicides.

During a Thursday news conference , Pennsylvania State Police Detective Joseph Vascetti announced charges against Brown in the 30-year-old cold case slaying of 45-year-old Bryce Kenneth Tompkins, of New Castle.

Tompkins body was found partially submerged in a Lawrence County creek on Dec. 26, 1988. An autopsy determined hed been shot twice in the back. According to Vascetti, Brown admitted to killing Tompkins because he was a witness to a burglary Brown had committed.

Up to this point, Brown has only been charged in Tompkins death. But officials say theres much more to this case.

Hes either been arrested for, or confessed to, or is a strong suspect in eight homicides right now in the northern part of the state from Lawrence County to Erie, Vascetti said.

The detective declined to provide additional information in the five other homicides. Its also unclear why, after so many years, Brown has allegedly decided to cooperate.

Brown faces multiple charges in connection with Thompkins slaying, including criminal homicide, aggravated assault and intimidation of witnesses, police said.

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