A former US medical student accused of murdering a masseuse he met through the classified ads website Craigslist has been found dead in prison in Boston.
The body of Philip Markoff, 24, was found on Sunday morning after an apparent suicide, police said.
Markoff pleaded not guilty to the fatal shooting in April 2009 of Julissa Brisman, 26, whom he met through Craigslist's erotic services section.
He was also facing charges of armed robbery and kidnapping.
Markoff was expected to stand trial next March for the murder of Ms Brisman and the armed robbery of a woman from Las Vegas.
He was also accused of attacking a stripper in Rhode Island during the same week.
Prosecutors say Markoff, a former medical student at Boston University, met all three women through Craigslist.
He was found dead in his cell at Nashua St Jail in Boston at 1017 local time (0417 GMT) on Sunday.
"Markoff was alone in his cell and all evidence collected thus far indicates that he took his own life," police and prosecutors said in a joint statement.
"Nonetheless, as with all such cases, a comprehensive investigation will be conducted to determine the facts and circumstances surrounding his death."
Markoff was engaged to be married at the time of his arrest, but his fiancee broke off the engagement. Saturday would have been the first anniversary of his wedding.
In the wake of Ms Brisman's murder, some law-enforcement officials accused Craigslist of promoting prostitution.
The San Francisco-based website subsequently removed its erotic services section, replacing it with listings for "legal adult service providers".
Forty million adverts - for jobs, housing and services - are posted on Craigslist each month.