Investigators enlisted a chemical-sniffing dog from the Florida state fire marshal's office on Tuesday to help determine if a New Year's blaze at a Pensacola abortion clinic was arson.
The two-story clinic that was gutted by flames early Sunday has been site of violence and protests for 30 years.
It was bombed on Christmas Day in 1984, and in 1994 a doctor and a volunteer who escorted patients to and from the clinic were shot to death as they arrived. The gunman, Paul Hill, was executed in 2003.
No one was hurt in Sunday's fire, which was reported around 1 a.m.
The Florida Fire Marshal's Office is heading the investigation, but the FBI and the Bureau of Alcohol, Tobacco, Firearms and Explosives have joined in because of the location of the blaze, said Deborah Cox, spokeswoman for the marshal's office.
"Because of the structure that was involved, because it was an abortion clinic," she said.
Samples of materials that were detected by the dog during a walkthrough of the fire site on Tuesday afternoon have been sent to a lab for analysis, Cox said. Results could take weeks, she said.
A preliminary investigation found that the fire began outside the clinic, Cox said.
Yellow crime scene tape stretched across the front entrance of the charred American Family Planning clinic Tuesday morning. The shell of the building concealed the burned-out interior that could be seen from the back. Investigators said late Tuesday that the clinic had been undergoing some renovations before Sunday's blaze and that paint and other possibly flammable materials were on site because of the work.
Clinic officials did not return phone messages left by The Associated Press seeking comment about the blaze.
The unassuming house-like structure fronts a busy street near a major north Pensacola intersection. Protesters often gather outside the clinic holding anti-abortion signs, Bibles or crosses.
The clinic's nearest neighbors include a largely empty office park well behind it and an auto parts store that is separated from the clinic by a large parking lot. Employees of the auto parts store declined comment Tuesday morning. Investigators said the clinic had not reported any threats or criminal activity recently. The clinic pays for off-duty Pensacola police officers to provide security.
The fire began in heavy fog and firefighters said the building was engulfed when they arrived.
Sheridan Loudon runs Acuharomony Wellness, a business located in the office park behind the clinic. Loudon's business includes acupuncture, chiropractic treatments, massages and facials.
Loudon said she decided to end her lease at the office park last month and move because of protests at the clinic.
"That place being there has been horrible for our business. They used to protest once a week and now they protest every day so we are moving," she said.
Loudon said that clients who pay for her services require a relaxing atmosphere.
"The energy there is negative," she said.
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