But when Johnson didn't recognize either man, he decided to involve people — a lot of them — to help crack the case. He posted a clip from a security camera on YouTube.com, Google Inc.'s video-sharing Web site, then e-mailed the clip's link to about 300 people and organizations saying the department was looking for the men.
"You don't have to be a technology wizard to figure out how to watch a video on YouTube," Johnson said of the decision to post on the site that hosts millions of amateur and commercial videos.
A handful of police departments have utilized YouTube as a law enforcement tool, putting up video of suspects and eliciting help from the Internet-using public in identifying them. Experts say the idea has promise, but it's too soon to tell whether it will have staying power amid constantly evolving technologies and the difficulty of making a video stand out among millions. Some also see a risk of fruitless tips, misidentifications or privacy problems.
In Johnson's case, the suspects were ultimately arrested. Though the video generated publicity and thousands of viewings online, Johnson is quick to credit the success to old-fashioned police work rather than the Web site.
"You've got to ask yourself, 'What's the penetration? How many people are going to watch it? What would make people watch it?" said Eugene O'Donnell, a former police officer and prosecutor who teaches at John Jay College of Criminal Justice in New York City.
Perhaps the most-publicized example was in Hamilton, Ontario, in Canada, where police in December posted a 72-second surveillance video on YouTube in hopes of locating a suspect in a fatal stabbing outside a hip-hop concert. Detective Sgt. Jorge Lasso said the video ultimately received more than 35,000 "hits," and police had enough information within two weeks for an arrest.
Lasso said it's hard to know exactly what role YouTube played since the clip generated so much media attention. While other departments that posted on YouTube simply relied on a press release to let the public know, Lasso went straight to the population that mattered and announced the clip on Web sites frequented by hip-hop fans.
"We hoped there would be enough buzz created that people on their own would go to YouTube," Lasso said.
While the key witness in the case told police he hadn't even seen the YouTube video, Lasso is skeptical of that claim.
"There's no way that I'm going to be convinced that a 20-something didn't view that YouTube posting," he said.
Police in Aventura, Fla., working on an open homicide case from 2001 posted video from a supermarket security camera showing the victim chatting with a younger man considered a person of interest in the case. Sgt. Michael Bentolila narrates the video, pointing out a tattoo or birthmark on the man's arm and telling viewers to note how the man walks.
Bentolila, who publicized the clip through a press release, said he had not yet received any solid leads.
"This is just something else — an extra added feature that we can now use to get our message out there on a countrywide or worldwide basis," he said.
More often, it's police who find themselves the subject of YouTube posts.
Groups that monitor police behavior use the site to post videos of arrests they believe involve excessive force or abuse. A clip of a Los Angeles officer repeatedly punching a suspect in the face surfaced on the site last year, triggering an FBI investigation.
But police are reversing that dynamic by displaying surveillance footage of suspects.
Experts say it's logical for departments to connect with the public via the web, especially younger Internet users more likely to visit YouTube and more likely, say, to have information about a stabbing outside a hip-hop concert.
"I kind of applaud the fact that police are using the latest tools," said Michael Brady, a retired police chief in Charlestown, R.I. who teaches criminal law and criminal procedure at Salve Regina University in Newport, R.I. "We tend to get stuck in technology deficits. We tend to want to stick with the old tried-and-true."
O'Donnell, the John Jay professor, said he liked that police were mining the public for information and said interest in real-life crime video speaks to the "natural inclination of people to want to play detective." But he worried that a department with limited resources could waste time responding to useless leads — or receive tips that are inconsistent.
A key question, he said, is "at what point do people just say 'another boring video"' and shut it off.
Robert Ellis Smith, a Providence-based privacy expert and publisher of the "Privacy Journal" newsletter, said video posted online should have the consent of bystanders or victims in order to protect their privacy. He also suggested the videos be dated and removed once any court proceedings are concluded.
"Victims of crimes are certainly entitled to be heard before that stuff is put on the Internet," Smith said.
Bentolila of Florida noted that in narrating the video, he specifically pointed out the suspect and focused viewers' attention on him. Lasso said he removed the clip within a day of the arrest being made.
"We're not asking anybody to say they are guilty or innocent," said Johnson, the Massachusetts officer. "The purpose of putting the video out is to identify them."
Marc Rotenberg, executive director of the Electronic Privacy Information Center in Washington, D.C. said, legally, police can post surveillance video online as long as it doesn't somehow falsely accuse or defame someone.
In the Massachusetts case, Johnson posted the video in December on YouTube's news and politics section after a man reported his truck had been broken into and his credit cards stolen.
The clip generated chatter from nearby police departments already investigating similar cases, and an officer in another town viewed the video and said he recognized the men, Johnson said.
But it wasn't until police in Middleborough, Mass., responded to a disturbance at a Holiday Inn that the suspects were arrested. Lt. David Mackiewicz, who was involved in the arrest, said he didn't recognize the men through YouTube and didn't even know their pictures were on the site.
"Technology," Johnson said, "will never replace the feet-on-the-street."