In August, city police received video from businesses and residents related to the slaying of Police Officer Moses Walker Jr. Surveillance video of two men trailing Walker released to the public led to tips identifying suspects Chancier McFarland and Rafael Jones. The two have been arrested and charged.
In January, Children's Hospital of Philadelphia physician Melissa Ketunuti's accused murderer, exterminator Jason Smith, was arrested after cameras at a Center City coffee shop and hospital placed him at the scene.
The Philadelphia Police Department in January estimated that it had solved more than 100 crimes in the past year due to tips that came in based on the release of surveillance footage. In addition to its own cameras, the city partners with agencies like SEPTA and PennDOT and property owners to access video.
But this type of constant surveillance has critics. In addition to claims that covering public space with cameras infringes on citizens' privacy rights, some say the use of video in criminal cases must be complemented by a comprehensive investigation.
Tahmir Craig's attorney, Joseph Oxman, said this wasn't the case when his client was arrested in May 2012 on murder charges in Chester. Craig, 23, spent 10 months in jail, accused of shooting 27-year-old Devon Williams.
Officials identified Craig after police released surveillance images, yielding tips that identified the suspect as Craig.
A subsequent analysis by the FBI showed the gunman to be taller than Craig and dismantled the case against him. Delaware County District Attorney Jack Whelan withdrew the charges in March and apologized for the error.
Craig has filed a federal suit against Delaware County, Chester and several officials.
"You need to use it as a tool," Oxman said of surveillance footage. "If you're going to base entire arrests off video, then you have the potential for incompetence and lazy police work."
Rob D'Ovidio, an assistant professor of criminal justice at Drexel University, agreed.
"You want to caution against the sole reliance," D'Ovidio said. It won't, he said, replace human investigatory work.
But the use of video, especially given advances in facial recognition and pattern-detecting technology, D'Ovidio said, can prove crucial to law enforcement. Surveillance cameras in the past two decades have been applied widely, in part due to the notion that they deter crime, he said.
"It's becoming so commonplace in major metropolitan areas," D'Ovidio said. "You'd be hard-pressed to walk a few blocks and not get picked up."
On Twitter: @AJFichera