Three months after a Franklin Township police car fatally struck a 10-year-old boy, the Gloucester County Prosecutor's Office issued a directive Tuesday requiring officers to use warning lights and sirens when their vehicles surpass speed limits by 20 m.p.h. or more.

Local police departments may impose more stringent policies, but the 20 m.p.h. clause provides a "ceiling" for officers during police responses, Prosecutor Sean F. Dalton said.

The prosecutor's office, which undertook its policy review after the Dec. 28 accident that killed Matthew McCloskey as he crossed Delsea Drive in Franklin, also established three countywide categories of police responses for the county.

The three "priority" levels, which further dictate when a cruiser must use warning lights and sirens, will also create consistent communication for the county dispatch system, Dalton said.

"There was quite a wide range of policies regarding motor vehicle responses and when a vehicle's lights and sirens needed to be active," Dalton said. "It made sense to update the language to ensure some uniformity in how we categorize the police calls for service."

McCloskey, a fifth grader at the Caroline L. Reutter School, was killed just after 7 p.m. as he crossed the road, Route 47, during a footrace with two friends, authorities said. The three had planned a sleepover.

A police car traveling at 74 m.p.h. - 24 m.p.h. above the posted speed limit - to a nonemergency call about an unruly juvenile struck and killed McCloskey. The car's warning lights and sirens were not activated.

The prosecutor's office, which investigated the death, did not file criminal charges against the police officer, Nicholas Locilento. McCloskey's mother, Michelle Harding, has said she might sue to pursue reforms.

"While it's too late for Matthew, she is very happy to see change so that this doesn't happen to anybody else," a family friend, Susan Cleary of Franklin Township, said Tuesday.

Pitman Police Chief Robert Zimmerman, president of the Gloucester County Chiefs of Police Association, said in a statement that his organization worked with Dalton during the review.

"Each police chief will still have the ability to craft their own policy inclusive of these county standardizations," the statement said.

Local departments must incorporate the criteria into their policies by May 1, the prosecutor's office said, and review their motor vehicle responses at least every 90 days to ensure compliance.

Dalton, who said he consulted the Division of Criminal Justice of the state Attorney General's Office, said he was unaware of any other county-mandated policies for warning lights and sirens. He said the Gloucester County standards would improve safety for police and the public.

"This review and directive was to provide some direction where previously there was very little," he said.