TARPON SPRINGS — It came as a shock when 74-year-old Dr. Steven Patlin Schwartz was found murdered in his home in May. He was married with five children and had built a thriving Dunedin medical practice.

But now comes a twist: The doctor, it turns out, murdered someone himself more than 50 years earlier, according to records obtained by the Tampa Bay Times.

Are the two crimes related? Tarpon Springs police investigators have not said. The May murder of Schwartz remains unsolved.

Schwartz was a 21-year-old University of New Mexico pre-med dropout who liked gambling when he concocted a plan with several others to rob local dentist V.G. Cook in November 1961, according to articles in the Hobbs Daily News-Sun from that era. Armed, Schwartz walked into the dentist's downtown office and told Cook he wanted his money.

"I had no bullet in the chamber of the gun, but he started shoving me, so I leveled one in and pointed at his forehead," Schwartz later told a group of high school students, according to another newspaper, the Hobbs Flare. "I put the gun right in front of his face and cocked it. He grabbed it and it went off."

A patient arriving for an appointment later discovered Cook's body. Schwartz was arrested days later and confessed that he tried to rob Cook because he was broke. Six others were also arrested. Nearly $500 was taken from Cook's office, according to newspaper accounts.

"I'm completely stunned at the charges against my son," his father, New York physician Felix Schwartz, told the News-Sun. "The death of Dr. Cook was a tragedy I deplore deeply."

Schwartz pleaded guilty to murder, was sentenced to life in prison, and placed in New Mexico corrections custody in March 1962, according to an agency spokeswoman.

In 1967, he was granted permission by a judge to visit several New Mexico high schools to talk to students about staying away from crime.

"The fatal shooting of Dr. Cook was a result of letting my big mouth get me into trouble and honesty with supposed friends," he told the students, according to the Hobbs Flare. "I feel I have done a lot of growing up, my sense of values is different. I certainly think there are a lot of things I did before that I wouldn't do again."

Schwartz was granted parole in 1971, when it was not uncommon for felons to serve far less than their full sentences. In 1977, at the age of 37, he was pardoned in New Mexico, records state.

He went on to receive a medical degree from the University of Torino in Italy and completed residencies in New York, according to his obituary. Schwartz started practicing medicine in Florida in 1985 and was certified in nephrology, which focuses on kidney illnesses and treatment. He has not been disciplined in the past, records show.

He lived with his wife, Rebecca Schwartz, in a house on Belcher Drive in Tarpon Springs, where he was killed last year.

On May 28, Rebecca arrived at the two-story home and found the house had been burglarized. Drawers in her bedroom were open. Money, jewelry and watches were gone, court records show.

She called police.

Inside, police dogs found Schwartz's body near the garage. He had been shot and stabbed, court records show. Detectives believe the doctor was targeted.

Several of Schwartz's family members declined to comment or did not return calls from a reporter Tuesday. One of his sons, Carter, sued Rebecca, his stepmother, last month on grounds that she declined to give him money for his education expenses, something Schwartz had promised him, according to the suit.

Carter was accepted into medical school the day his father was killed.

Times staff researcher Carolyn Edds contributed to this report. Contact Laura C. Morel at lmorel@tampabay.com or (727) 445-4157. Follow @lauracmorel on Twitter.