To police, it is the witness that never lies, never forgets, never changes its story. And while its vision often is blurred, it sees much that others miss.
The electronic eye of the surveillance camera has become a treasured tool of criminal investigators. As the gaze of security cams permeates stores, lobbies, sidewalks, schools, parks and parking lots, so have its date-stamped images risen on a detective's checklist.
"Video gives you definitive answers; it's not left to subjective memory or someone's recollection or someone's lies," said Camden County Prosecutor Vincent Sarubbi. "You see it in black and white, and you know whether or not it happened."
An estimated 1.3 million surveillance cameras are operating in the United States, said Joe Freeman, head of J.P. Freeman Co. Inc., a leading consultant to the security industry. That's up by as much as 30 percent over the last five years, he said, with office buildings and banks being the primary users.
Philadelphia police are hoping for a tech-assisted break in the baffling predawn slaying of a hospital worker last week in Center City.
Cameras mounted on a federal building yielded grainy images of a man shooting Patricia McDermott at 4:45 a.m. May 17 on a Ninth Street sidewalk. Police have publicized those images while scouring nearby security cameras for more glimpses of suspects and witnesses.
"It is one of the most important things to law enforcement right now," said Bucks County District Attorney Diane E. Gibbons. "Where before we would have to rely solely on witnesses' descriptions of a suspect, now every time there is a major crime, one of the first things we do is to look for any and all videotapes in that area."
Last month, Gibbons' detectives used surveillance photos to solve a slaying just as vexing as the McDermott shooting.
William L. Berkeyheiser, an affable retired health-care executive, had been gunned down inexplicably on Easter at the door of his Upper Makefield home. A day later, investigators learned that shortly before the shooting, a man had stopped at a nearby convenience store and asked for directions to Berkeyheiser's street.
The man's image was captured by a store surveillance camera and publicized. A flood of tips ensued, one leading to Stanford Douglas, a onetime coworker who confessed to shooting Berkeyheiser over a racial joke Berkeyheiser allegedly had told in 1997.
"We would not have solved the case without that tape," Gibbons said.
Such opportunities will only expand as the post-9/11 demand for security equipment grows. Prosecutors in the Philadelphia region and other urban areas already have abundant tales of cases solved or aided through surveillance photos or videos.
In 1999, the man who fatally stabbed Philadelphia Daily News columnist Russell Byers outside a Chestnut Hill Wawa store was identified from surveillance tapes.
In 2000, exotic dancer Rachel Siani was allegedly dumped, while unconscious, from a Delaware River bridge in Burlington County. A bridge camera captured an image of a woman's body lying in the bed of the pickup truck of her accused killer.
And in Montgomery County, a man accused of raping and fatally stabbing 19-year-old Anna Nicole Fowler last year in a King of Prussia motel faces a double video whammy. Cameras captured him checking into the motel before the slaying, and using the victim's ATM card afterward.
There are prominent national examples as well.