YARMOUTH — As news spread Thursday that new DNA evidence likely identified his client as the Boston Strangler of nearly 50 years ago, F. Lee Bailey reacted by simply saying he already knew.

The famed-criminal defense attorney of six decades said Friday afternoon that his client Albert DeSalvo, who died in 1973 in a prison stabbing, confessed to the sexual assaults and murders that petrified Bostonians in the early 1960s. He said because DeSalvo was never prosecuted, a mystery was created around the unsolved murders, but he never had a question in his mind.

“He was the Boston Strangler,” said Bailey, who is currently awaiting an appeal to the Maine Supreme Judicial Court ruling earlier this month saying he can obtain a license to practice law in Maine. “Albert was a very well documented serial killer, but he was never tried for it.”

Bailey said he supports the move to exhume DeSalvo’s body to get a DNA sample, a step announced Thursday by a Massachusetts prosecutor who said that advances in DNA technology have allowed investigators to link DeSalvo — through a saliva sample from his nephew — to the last Boston Strangler victim.

The new forensic evidence should give closure to the family of 19-year-old Mary Sullivan, who was found strangled in her apartment in January 1964 and was the last of 11 women murdered between 1962 and 1964 by the Boston Strangler, Bailey said.

While some have said DeSalvo’s confession had holes and that the modus operandi was not the same for all the murders, Bailey said he knows DeSalvo was “absolutely the guy” because of evidence he provided that only the killer would know.

“I asked police to give me five questions that could not be answered by a guy who didn’t do it,” Bailey said, adding the details DeSalvo gave police were enough to convince him.

For example, DeSalvo told police that 20-year-old Sophie Clark, who was found Dec. 5, 1962, sexually assaulted and strangled with nylon stockings, was menstruating, he said.

“When he came out with that [all questions disappeared],” Bailey said.

His client was never prosecuted because of some legal maneuvering.

“I devised a method for Albert to tell the police whatever he knew and he would not be prosecuted,” Bailey said. “The man was declared incompetent,” was given a distinguished lawyer as a guardian, and then sent in to talk to police.

“Without benefit of DNA, they said he was the guy,” Bailey said.

DeSalvo is buried in Peabody, Mass.