Updated

Paul Hill (search), the former Presbyterian minister convicted of murdering an abortion doctor, died on Wednesday by lethal injection. He was the first person executed in the U.S. for anti-abortion violence.

Hill, 49, was found guilty of the 1994 shotgun slayings of Dr. John Britton (search) and his bodyguard, retired Air Force Lt. Col. James Herman Barrett (search), in Pensacola, Fla. Barrett's wife, June, was wounded.

Death penalty opponents and others called on Gov. Jeb Bush to halt the execution, some of them warning Hill's death would make him a martyr and unleash more violence against abortion clinics. The governor said he would not be "bullied" into stopping the execution, the third in Florida this year.

The governor's office said Hill was pronounced dead at 6:08 p.m. EDT.

Florida abortion clinics and police were on heightened alert for reprisals. Several officials connected to the case received threatening letters last week, accompanied by rifle bullets.

"Paul Hill is a dangerous psychopath," said Marti McKenzie, spokeswoman for Dr. James S. Pendergraft, who runs clinics in Orlando, Ocala, Tampa and Fort Lauderdale.

Outside Florida State Prison, extra law enforcement officers, explosives-sniffing dogs and undercover officers were in place to prevent protests from getting out of hand. About 50 abortion and death penalty foes quickly left following the execution as rain fell and lighting struck near the prison.

Hill had final visits with his wife and son, his mother and father and two sisters. His two daughters visited him earlier in the week. His religious adviser stayed with him until just before his execution.

Since losing his automatic appeals, Hill has not fought his execution and insisted up to the day before his death that he would be forgiven by God for killing to save the unborn.

"I expect a great reward in heaven," he said in an interview Tuesday, during which he was cheerful, often smiling. "I am looking forward to glory."

Hill suggested others should take up his violent cause.

Fringe elements of the anti-abortion movement that condone clinic violence have invited attacks on Web sites that proclaim Hill as a martyr. Members of the mainstream anti-abortion movement have denounced the calls for violence.

Most abortion clinics in Florida reached by The Associated Press on Wednesday declined comment. McKenzie said security is always high at their clinics, but they are particularly cautious now because of Hill's call for people to follow his actions.

"The bottom line is when you work in the industry you're aware those people are out there every single day," she said.

Inspired by the 1993 shooting death of another abortion doctor in Pensacola, Hill purchased a new shotgun and went to a gun range to practice. The morning of the murder, as Britton and the Barretts entered the clinic parking lot, Hill shot James Barrett in the head and upper body. He then reloaded and fired again, hitting Britton in the head and arm. June Barrett was wounded in the arm.

Hill put down the shotgun because he did not want to get shot by police and walked away. When officers arrested him within minutes without incident, he said, "I know one thing, no innocent babies are going to be killed in that clinic today."

Hill was the 57th inmate executed since Florida resumed executions in 1979 and the third in Florida this year.

The killings of Britton and Barrett happened during a time of increased violence at clinics nationwide.

Another abortion doctor had been killed in Pensacola in 1993 by Michael Griffin, who is serving a life sentence. Two receptionists were killed at Boston-area abortion clinics in 1994 by John Salvi, who committed suicide in prison two years later.

Earlier this year, James Kopp was convicted of killing an Buffalo, N.Y., abortion doctor in 1998, while fugitive Eric Rudolph was captured and charged with a 1998 bombing that killed an off-duty police officer at an Alabama abortion clinic.

The Associated Press contributed to this report.