A child psychiatrist who once headed the American Academy of Child and Adolescent Psychiatry was arrested amid allegations he molested male patients dating back nearly four decades.

Dr. William Ayres, 75, was taken into custody Thursday at his San Mateo home and charged with 14 felony counts of lewd and lascivious acts with a child under 14.

Ayres allegedly fondled three boys repeatedly between 1991 and 1996 while they were his patients, according to the complaint. The statute of limitations for such crimes is 10 years or until the victim turns 28 years old. The alleged victims are now 21, 25 and 26.

"We have many other victims who are outside the statute of limitations," said prosecutor Melissa McKowan, adding their testimony will be used at trial to show a pattern of behavior. The earliest case she's aware of is from 1969.

Thursday's arrest followed a four-year investigation.

Ayres, a prominent psychiatrist who retired last year, had been honored in 2002 by the San Mateo board of supervisors with a lifetime achievement award for "his tireless effort to improve the lives of children and adolescents." He also served as president of the academy from 1993 to 1995.

"The real tragedy here is that parents entrusted their children to this doctor for help, and they were victimized while in his care," San Mateo police Capt. Mike Callagy said. "That's so tragic."

Ayres was being held on $1.5 million bail and was scheduled to be arraigned Friday.

His attorney did not return a phone call seeking comment and The Associated Press was not immediately able to reach Ayres' family.

Suspicions have dogged Ayres since 2003, when one former patient sued, accusing him of molesting him under the guise of a medical exam on several occasions in the late 1970s when the patient was 13.

In July 2005, the two sides reached a confidential settlement in which Ayres' attorney said the psychiatrist did not concede any wrongdoing.

Ayres said under oath that he didn't remember the alleged victim and denied molesting him. He acknowledged that he sometimes conducted physical exams of patients, according to a transcript of his deposition in the lawsuit.

"I do not think there is any standard of care that says it's inappropriate for a physician who is a child psychiatrist, that they should not do physical examinations," Ayres said, according to the transcript.

At least two other molestation reports against Ayres arose before the lawsuit, but one was determined to be "unfounded" in 1987, and the other alleged victim wouldn't cooperate with police, according to court records.

In 2005, at least two other men said Ayres molested them when they were teens in the 1960s and 1970s, but authorities couldn't proceed with the cases because the statute of limitations had expired, police reports show.

A spokeswoman for the Medical Board of California said Ayres' license to practice doesn't expire until January and he has no record of complaints.