In September 2004, the department's crime lab matched male DNA taken from both the McKeown and Sokoloff crime scenes, police said. But they couldn't match the DNA to a suspect. Over the next five years, detectives developed 14 suspects, but their DNA ruled each of them out as the attacker.
The break came last October, when two officers collected DNA from Thomas as part of an ongoing process to swab registered sex offenders. On March 27, the California Department of Justice DNA Laboratory notified detectives that his DNA matched the evidence from the Sokoloff slaying.
On March 31, they were told that his DNA matched the four other slayings. He was arrested later that day. Thomas is being held at L.A. County Jail and could not be reached for comment.
Police said that connecting the dots in such cases was much harder before DNA and computer databases.
"It was harder to make connections," said LAPD Deputy Chief Charlie Beck. "The difference in investigative techniques, communication and the science is huge."