Locked in a struggle with a suspected shoplifter who tried to grab his gun from its holster, Pittsburgh police Officer William Kunz reached for another weapon -- a knife with a 2-inch blade he kept in his duty belt.

He stabbed the man once in the abdomen during the fight on Sunday at Burlington Coat Factory, a move that police have said likely saved his life.

The knife wasn't standard-issue; many officers keep them for cutting anything from crime scene tape to the seat belts of trapped car crash victims. But like other tools that aren't department-issue -- handy items like flashlights, binoculars and pens -- the utility knife quickly became the officer's weapon of last resort.

"You never know what you might need if you can't get to another weapon on your belt," said Officer Don Adamsky, an instructor at the Pittsburgh Police Training Academy. "When it's a life-or-death situation, you use what you can grab."

Screwdrivers, ratchets, digital cameras, window scrapers, shoelaces and a number of other items you might find on an officer's duty belt or in his gear bag are there because years of experience have proven them to be invaluable.

Officer Adamsky, for instance, learned as a rookie that his knife was useful, mostly for cutting the strings off the "No Parking" signs dangling around parking meters.

Officers can carry with them almost anything that isn't illegal or cumbersome -- no machetes, brass knuckles, switchblades or "Crocodile Dundee knives," academy director Lt. Karen Dixon said.

"Nobody tries to carry anything bizarre," she said. "This is the stuff we know we're going to need."

When they join the force, officers are given the minimum, including a duty belt, a radio holder, a single set of handcuffs, rubber gloves, a canister of pepper spray, and a holder for bullets, which they receive when they purchase their own guns, choosing from several makes and calibers.

Each gun is a roughly $500 investment, said South Side Officer Daniel O'Hara, president of the city's Fraternal Order of Police. Officers can carry up to two guns.

"It's a backup weapon," he said. "For if your gun jams."

Officers must also buy their own expandable batons and holders for them. Tasers are popular, but officers must request them and also must be trained before they can carry one.

After that, it's up to an officer to decide what else he might need or where to stash it, on a duty belt, in a bag, in a spare pocket or a boot.

Mike Havens, a 17-year veteran who patrols the Hill District, stashes two large gear bags in his cruiser. Items inside include: a digital camera, a tool kit, a ratchet set, Allen wrenches, a first aid kit, three flashlights (in case two give out), rechargeable batteries and a car adapter, a face shield and gloves, a folding knife and a small window scraper -- for quick removal of phony inspection stickers.

"It's all tools of the trade," he said.

Officer Hank Rogowski, who patrols on the South Side, keeps a blackjack -- a small nightstick -- and a second pair of handcuffs, which have proven helpful in rough-and-tumble situations. The city-issued cuffs are linked by a small chain, while his are hinged and can be used on suspects with wider wrists or even as shackles, he said.

Officer Rogowski, whose 25 years in law enforcement include a nine-year stint as a University of Pittsburgh officer, also packs a knife.

"But I always have that," he said. "You never know when it could come in handy."

Sgt. Eric Kroll once used his night stick to break a car window, freeing a woman who was trapped inside. Officer Dan Stangrecki, who carries binoculars and patrols the North Side, said he once worked with an officer who could secure an unlocked door with only a shoelace.

"This is your office," Officer Adamsky said, referring to the array of tools and weapons officers carry. "You don't have to go back to the station."

Officer Kunz, who is off duty while recovering from his injuries, has declined to comment about the experience at Burlington, during which he spotted a suspect shoplifting Timberland boots.

The suspect, later identified as Anthony Smith, 59, of Knoxville, has been charged with aggravated assault, retail theft, reckless endangerment, resisting arrest and disarming a law enforcement officer.

When he confronted Mr. Smith and tried to cuff him in the store's small loss prevention office, a criminal complaint says, Mr. Smith began punching him with the cuffs and both men fell to the ground, where Mr. Smith tried to pull his gun from its holster. Mr. Smith let go of the gun after he was stabbed, police said, and a responding officer used a Taser to subdue him.

Officer O'Hara praised Officer Kunz's quick action, saying he had the tools on hand to protect himself and others.

"When you have someone who is trying to cause great harm to the public, you need to use whatever you have available to you," Officer O'Hara said. "Once the person goes for your firearm, you do what you can do to end the threat."