A serial killer already on death row in Oklahoma pleaded guilty Wednesday to three cold-case murders in Texas and was sentenced to life in prison.

William Lewis Reece, 62, first pleaded guilty in a courtroom in Galveston in the 1997 slayings of 12-year-old Laura Smither and 17-year-old Jessica Cain.

He was then transferred to nearby Angleton to enter a guilty plea in the disappearance and murder of 20-year-old Kelli Cox.

In each of the three cases, Reece received a life sentence, which he cannot appeal.

“Twenty-five years is an awfully long time to be waiting for justice and there were a number of years in there where we truly didn’t think we’d ever see this day,” said Laura Smither’s mother, Gay Smither, according to KPRC.

Reece was serving a 60-year prison sentence for the 1998 Texas kidnapping of Sandra Sapaugh in 2016 when he began cooperating with investigations of the other cases.

In 2021, he was sentenced to death for the 1997 killing of 19-year-old Tiffany Johnson in Oklahoma City.

Reece carried out the killing spree in Texas and Oklahoma over a five-month period in 1997, after he had already served 10 years in Oklahoma state prison for raping two women.

Smither failed to return from a morning jog in Friendswood in April 1997. Her remains were found more than two weeks later about 30 miles away in a retention pond in south Houston.

On July 15, 1997, Kelli Cox, a 20-year-old criminology student at the University of North Texas, was leaving a tour of a Denton jail when she discovered she had locked her keys in her car, reported Fox 26.

Cox walked to a nearby gas station to call her boyfriend. She was never seen alive again, leaving behind a young daughter.

Just two weeks later in Bethany, Oklahoma, Tiffany Johnston, a 19-year-old newlywed, was abducted from a carwash. Her body was discovered the following day in a field in Yukon. She had been raped and strangled.

In August 1997, Jessica Cain went to a party to celebrate her performance in a high school musical. Her truck was later found abandoned near her home on Tiki Island, Texas.

In October of that year, Reece was arrested for the aggravated kidnapping of Sapaugh. He was convicted of that crime in 1998 and sentenced to 60 years in prison.

While he was serving his term in Texas, investigators in Oklahoma linked Reece to Johnston’s rape and murder and charged him in that case.

Hoping to secure a more lenient sentence, Reece began talking to the authorities and confessed to the murders in Texas after getting a promise from a Ranger that prosecutors would not seek the death penalty.

In the spring of 2016, Reece led cops to Cain’s remains in a pasture in south Houston, and to Cox’s remains in rural Brazoria County.

In court Wednesday, some of the victims’ relatives gave emotional impact statements, describing the anguish of their loss.

Gay Smither, Laura’s mother, thanked her daughter’s killer for telling the truth about what happened and told him she forgave him, after languishing in “a prison of anger and rage.”

Alexis Bynum, Cox’s daughter, was just 19 months old when her mother was murdered. She said she had spent years searching for her missing mom.

“At the end of the day we’re able to shut the chapter on this part of it and not have to worry about him hurting anyone else,” Bynum said.

With Post wires