In San Diego, a man shoots at a store clerk; in Orlando, Fla., thieves snatch a dozen puppies from a breeder's kennel; in Houston, an arsonist isn't caught in the act when he torches a nightclub, leading to a fireman's death, but cameras see him buying the gas cans and filling them up, and a jury gives him life in prison.
In each case, police looking for evidence and witnesses asked the same question when they hit the crime scene.
"Is there video surveillance we could get a hold of?" says John Firman, research director at the International Association of Chiefs of Police.
Law enforcement agencies worldwide are relying more than ever on surveillance video because there's simply more of it, including their own cameras, and those that have become ubiquitous inside and outside homes and businesses because of security concerns.
Another reason?
"The prices went down," laughs Firman.
He's right — cameras are cheaper and better than ever, with much more memory capacity — which means a camera, if not Big Brother, is likely watching you. In London, 500,000 surveillance cameras mean the average Londoner is caught on tape around 300 times a day.
Even at NBC News headquarters in New York, when I go from the visitor's center just a few steps to the main elevator bank, no fewer than four cameras get a good look at me.
But critics say it's easy to misinterpret video. For example, Hollywood police called a dramatic press conference to ask for help in a kidnapping caught on tape that turned out to be a domestic dispute with no crime committed.
"We need to be on guard here a bit, ensuring that when technology is used, it's effective and respects constitutional principles," says Marc Rotenberg with the Electronic Privacy Center.
Rotenberg says the Tom Cruise movie "Minority Report," about the abuse of ultra-sophisticated surveillance techniques, makes an important point.
"There is a real danger in placing too much faith in any technology that promises to eradicate crime," he says.
But cameras can help solve crimes, critics admit — from puppy snatchings to finding the suspects in the murder of an actress in New York City. The rest, especially prevention, is what it's always been — just good police work.