JACKSONVILLE, Fla. -

Police are searching for a shooter after a 50-year-old woman working as a roving security guard was found dead in a truck at a Southside McDonald's.

Sgt. Shawn Coarsey said police responded to the McDoanld's on Bonneval Road off J. Turner Butler Boulevard about 5:40 a.m. after someone reported a woman, identified as Brenda Williamson, appeared to have been shot in the chest while sitting in a security truck. She was not armed.

"When they arrived, they found a white female," he said. "It looks like she suffered from one gunshot wound. She was pronounced deceased at the scene. JSO homicide responded and we are actively conducting the investigation."

Suspicious deathMcDonald's murder pickup truck Police said Williamson was an unarmed roving security guard that was working Wednesday night for Universal Protection Service, just down Philips Highway near where the shooting happened. She was scheduled to get off at 6 a.m. Thursday.

A manager at the company only felt comfortable saying the victim's co-workers are "very, very saddened" and that she was a "good officer."

"She moved around but the McDonald's was not one of her spots," Coarsey said. "The drive-through was open only. They didn't hear anything there."

Police suspect foul play in the woman's death, but they do not have any information on a possible suspect or suspects.

Police have not found any witnesses that saw what happened yet, but say some people passing through McDonald's told them they saw the woman but thought she was sleeping in her truck.

"We're interviewing witnesses, hospital witnesses, looking for video surveillance," Coarsey said. "Right now we don't have a motive, we don't know. It could be robbery, but we don't know at this point."

Police said it didn't appear that Williamson went through the drive-through, and they're trying to figure out why she was there.

Her body was taken to the Medical Examiner's Office for an autopsy.

The McDonald's reopened after police closed the scene for several hours during the investigation.

Ed Orlando, the vice president of North Florida Training and Security Associates, said his company has trained nearly 20,000 people to become licensed security guards, some armed and some not.

"In most cases, it's foreseeable by the individual that something's going to happen, and if they take the wrong action, they can end up dying," Orlando said, adding that he doesn't know what happened specifically in this case. "The main issue is to be ready."