Police believe a 72-year-old insurance claims adjuster arrested earlier this month is the most prolific serial killer in the city's history, having raped and strangled as many as 30 older women over two decades.
The break in the cold case came in October when John Floyd Thomas Jr., who had twice been convicted of sexual assault, had a DNA sample taken as part of an effort to build an offender database.
Thomas was charged April 2 with murdering one woman in 1972 and another in 1976. DNA matching Thomas' was found at three other crime scenes in the 1970s and '80s, Los Angeles police cold case Detective Richard Bengston told the Los Angeles Times in a story published Thursday.
Detectives now consider Thomas also a suspect in two waves of killings that left at least 22 women dead based on the circumstances of the crimes, the newspaper reported. It could not be immediately determined where the other killings took place.
"When all is said and done, Mr. Thomas stands to be Los Angeles' most prolific serial killer," Bengston told the newspaper.
Thomas was being held in county jail and could not be reached for comment. Authorities reached by phone by The Associated Press did not know whether he had obtained an attorney.
Thomas was sentenced to six years in 1957 for burglary and attempted rape in Los Angeles. Two parole violations sent him back behind bars until 1966.
In the first wave of killings in Los Angeles in the mid-1970s, a man police dubbed "The Westside Rapist" entered the homes of dozens of elderly women who lived alone, raped them and choked them until they passed out or died. The 17 people killed were found with pillows or blankets over their faces.
During that time, Thomas was a social worker, hospital employee and salesman. The attacks stopped in 1978 -- the year Thomas went back to prison for the rape of a Pasadena woman.
After his 1983 release, he moved to Chino in San Bernardino County and took a job as a hospital peer counselor in nearby Pomona. That year, a series of attacks on elderly women began that included five slayings in the nearby Los Angeles County town of Claremont. The attacker also used blankets or pillows over his victims' faces.
Despite some 20 survivors, detectives didn't connect the two cases. There were conflicting descriptions from victims, a lack of communication between agencies and an absence of DNA technology.
Since 1989, Thomas worked at the State Compensation Insurance Fund in Glendale. He was arrested at his South Los Angeles apartment on March 31.