Los Angeles police believe they have caught a serial killer responsible for the rape and murders of up to 30 elderly women in two separate waves of rampages in the 1970s and 1980s.
John Thomas, 72, is being held in the city's county jail after being linked through DNA samples to five killings. Police suspect him of being the notorious "West Side rapist" who spread terror over many years among lonely older women.
He was arrested last month and charged with the deaths of Ethel Sokoloff, 68, in 1972, and Elizabeth McKeown, 67, four years later. DNA tests have linked him to three other murders, but officers are interested in a further 25 killings that they think he may have perpetrated as well as dozens of rapes and sexual assaults.
"When all is said and done, Mr Thomas stands to be Los Angeles' most prolific serial killer," Richard Bengston of the LAPD told the Los Angeles Times.
Even at a time when LA had a reputation for violence, drugs and gangs, the spate of rapes and killings stood out as singularly grim and disturbing. The attacks were focused on the Wilshire area to the west of the city, just south of Hollywood and close to Thomas's then home. Over a six-year period beginning around 1972 there were up to 19 murders and more than 20 other sexual assaults in the neighbourhood.
A second wave of killings occurred between 1983 and 1989 in Claremont, 30 miles east of downtown LA. The dates and locations coincide with Thomas's movements. In 1978 he was sent to prison for five years for a single rape, moving after his release to an area adjacent to Claremont.
Most of the victims were single women, often widows, many in their 70s and 80s; one was 92. The attacks happened late at night and appeared to have been meticulously planned. In all cases, the victims were strangled and had a pillow or blanket placed over the face.
The killer preyed upon his victims' vulnerability. Some were blind, others deaf or only partially able to walk.
A neighbour of the 92-year-old victim told a Los Angeles Times reporter in 1974 that the victim "couldn't even walk anymore. She'd just sit there on her porch and rock all day long."
The potential breakthrough in the investigation gives the LAPD the chance to atone for its past inability to bring the killer to justice. Despite more than 20 survivors coming forward at the time to testify, the police were unable to make headway as witnesses gave wildly conflicting accounts of his appearance.
The new hope stems from the application of DNA forensics to these cold cases. Five years ago officers were able to connect the Sokoloff and McKeown attacks to the same DNA sample, but at that stage they could go no further as Thomas was not on the DNA database.
Then last October his DNA was collected as part of a routine process of swabbing registered sex offenders, and gave a positive match.