Google's real-time traffic app Waze is being criticized by some law enforcement officials who say its police-spotting feature could endanger officers. Los Angeles Police Chief Charlie Beck is among the critics.
Beck said Tuesday the app could be used by criminals to target police or to evade officers.
"It is not always in the public's best interest to know where police are operating," Beck said.
"There is a criminal element," he said, "who are able to ply their trade and craft more effectively by knowing where police are."
Beck in December wrote a letter to Google, which acquired Waze in 2013, saying officer safety is compromised because the app points out police locations.
A Waze spokeswoman said in response that Waze's "police partners" including the New York Police Department were supportive and that the app actually promoted safety.
"Most users tend to drive more carefully when they believe law enforcement is nearby," said Julie Mossler. She said the police-spotting feature allowed users to place an icon on a map that gave a rough location -- not an exact one -- and that it didn't enable users to "track" police.
Beck said that, although he understood Waze's point on better driving, the risks of the feature outweighed its benefits.
"You have to constantly weigh what is the value of information you are putting out versus the risks you create," he said.
In Beck's letter to Google, he said that Ismaaiyl Brinsley monitored police movements with Waze in the days before he killed New York police Officers Rafael Ramos and Wenjian Liu on Dec. 20.
Beck clarified on Tuesday that he wasn't saying the gunman used the app to find the officers, but "it could be used for those purposes, and I don't think that risk -- no matter how small it is -- is outweighed by the benefit."
The chief acknowledged that even if Waze were to remove the police-spotting feature, someone else could come up with a similar app.
"That is why it is important to have this discussion," he said.
The Associated Press, which first reported on police concerns about Waze, said the issue was raised at a National Sheriff's Assn. meeting in Washington.
At the meeting, Sheriff Mike Brown of Bedford County, Va., called on Google to "act like the responsible corporate citizen they have always been and remove this feature from the application even before any litigation or statutory action."