Photo: The Canadian Press. All rights reserved.

FILE - In this Monday, March 4, 2013 file photo, Samuel Little appears at Superior Court in Los Angeles. (AP Photo/Damian Dovarganes,File)

DNA evidence taken from the clothing and body of Carol Alford a quarter-century after her death linked her slaying to a serial killing suspect with such certainty that no other person on Earth could have deposited the cells, an expert testified Tuesday.

Forensic DNA analyst Amanda Mendoza was asked during the trial if she had made a positive match of the DNA to defendant Samuel Little.

"That's correct," she said after tossing out extravagant statistics.

Alford was the first of three women whose killings were being scientifically dissected for jurors at the trial. The cold cases had baffled authorities for decades until the DNA technology made prosecution possible.

Little, 74, could face life in prison if he is convicted of killing the three women who were found nude below the waist after being dragged into debris-strewn alleys.

He was arrested in 2012 after detectives from Los Angeles found him living in a Christian shelter in Kentucky.

His 100-page rap sheet details crimes in 24 states spread over 56 years — mostly assault, burglary, armed robbery, shoplifting and drug violations. In that time, authorities say, he served less than 10 years in prison.

Los Angeles authorities say they linked the former boxer to the three killings through evidence recovered at scenes and his DNA data stored in a criminal database.

Prosecutor Beth Silverman called witnesses to show that Alford fit the pattern of victims in the case. She had cocaine in her blood, had been strangled and had semen on her clothing but was not raped.

The victims were Alford, 41, who was found on July 13, 1987; Audrey Nelson, 35, found on Aug. 14, 1989; and Guadalupe Apodaca, 46, found on Sept. 3, 1989.

The trial is the first involving murder charges against Little, but Silverman said outside court he is likely responsible for at least 40 killings nationwide dating back to 1980.

Authorities in California, Florida, Kentucky, Missouri, Louisiana, Texas, Georgia, Mississippi and Ohio are scouring their cold case files for possible ties to Little.

Darryl Lee, a police officer who went to the scene of the Alford killing in 1987, testified he remembered it well. It was one of the first homicides of his career and he said he pulled his police car across the alley to shield the half-naked woman's body from a gathering crowd "to give her a little dignity."

"It appeared to me the crime didn't happen there and the victim was dumped," he said.

He called Alford's daughter to the scene to identify the body and said when she saw her mother, "She screamed and started crying."