Recent posts from the department's page, Munhall Crime Watch, provided information on a sex offender who just moved into the borough, assisted Allegheny County police as they searched for suspects in a homicide at The Waterfront and helped county sheriff's deputies track down a fugitive.
With bitter cold temperatures expected this week, the department has posted information on school closings, warming centers and garbage pickup.
"We use it for everything," said Officer Dan Boehme, community relations officer at the Munhall Police Department. "Community notifications, crime maps, safety tips, road closures, tips on crime trends -- you name it. Whatever we can put out there, we put out there."
Munhall isn't alone. As social media sites grow, so do their importance to police departments.
Nearly 96 percent of police departments use social media in some capacity, according to a recent survey by the International Association of Chiefs of Police. Facebook is the most common, followed by Twitter and YouTube. Munhall's Facebook page gets between 10,000 and 15,000 views a week, Boehme said.
Police in Cranberry and Monroeville do not have Facebook pages but still use social media to help with investigations. Recently rehired Monroeville police Chief Doug Cole said the department intends to restart its Facebook page. Cranberry recently took over a police page started by a citizen, and plans to restart it soon, Sgt. Chuck Mascellino said.
"Departments have been using them for awhile," Mascellino said of Facebook and other social networks. "We're typically technologically savvy, but we're probably one of the last departments in the area to get onto social media."
The rise of social media has forced police departments to take notice, said Tony Gaskew, director of criminal justice at the University of Pittsburgh-Bradford. Monitoring a person's Facebook page is the new wiretap. The wanted poster once tacked up at the post office can now be sent to people's smartphones, Gaskew said.
"Social media has tremendous benefits not just in investigatory work but in public interaction," Gaskew said. "It is probably one of the greatest investigative tools available to law enforcement."
The chiefs association found that 86 percent of departments use social media to investigate crimes, 80 percent reported solving a crime with help from social media, and 73 percent said social media have improved communications with their communities.
As an investigative tool, police agencies are finding significant value in posts left on social media sites. The Pittsburgh Bureau of Police has no official Facebook page, but detectives scour social media sites for clues, said Diane Richard, spokeswoman for the department. The same is true in the Allegheny County District Attorney's Office. Prosecutors have introduced Facebook photos of defendants posing with guns as evidence in trials, said Mike Manko, the department's spokesman.
In Mt. Lebanon, detectives use social media to track known drug dealers, said Deputy Chief Aaron Lauth. A person's Facebook friends or Twitter followers can give officers a virtual look at the suspect's distribution network or known associates. Several ongoing drug investigations are relying on information found on Facebook, Lauth said.
The department's Facebook page and a new service allowing people to anonymously text tips to police helped locate a teenager from Castle Shannon missing in one of Mt. Lebanon's parks, Lauth said.
Photos of suspects in a Dec. 12 shooting on McFarland Road were posted on Facebook, and so was a photo of a missing dog. Residents also send in tips about who is driving on a suspended license or who frequently drives under the influence.
"It's a medium that people are using, and that's why we wanted to jump on board," Lauth said.
Occasionally, Mt. Lebanon police receive messages that should have gone to a 911 dispatcher, Lauth said. Several officers can access Facebook from their smartphones and respond while on the road, but Lauth and others post frequent reminders that Facebook is not a replacement for dialing 911.
"Police departments have to educate the public on the proper use of social media," Gaskew said, and send the message that police aren't monitoring the social media site continuously.
Police departments should educate officers on the proper use of social media, Gaskew said. Fewer than half of departments have social media policies, he said, and that needs to change.
Defense attorneys have used posts from an officer's personal Facebook page to discredit or impeach testimony at trial, Gaskew said. The chiefs association warns officers to think about each post and picture.
Monroeville police have a social media policy, but it needs to be updated, Cole said.
"We need to look at it, too -- what can you and what can you not disseminate?" Cole said. "This is technology jumping us again."