According to the document police chief Charlie Beck sent to Google CEO Larry Page on December 30, people are using the "unwitting" Waze community as "their lookouts for the location of police officers."
Waze is a traffic and navigation application that users contribute information to in order to share real-time road information.
Beck said the shooter in a recent double murder of two New York police officers used the application to track the location of cops.
"I am concerned about the safety of law enforcement officers and the community, and the potential for your Waze product to be misused by those with criminal intent to endanger police officers and the community," the letter said.
Ismaaiyl Brinsley, 28, killed police officer Wenjian Liu and his partner Rafael Ramos in December while they sat in their squad car.
Waze rejected the allegation, arguing that the application is welcomed by many law enforcement agencies.
"We think very deeply about safety and security and work in partnership with the NYPD and other police and departments of transportation all over the world ... to help municipalities better understand what's happening in their cities in real time. These relationships keep citizens safe, promote faster emergency response and help alleviate traffic congestion," said Waze spokeswoman Julie Mossler.
"Police partners support Waze and its features, including reports of police presence, because most users tend to drive more carefully when they believe law enforcement is nearby."