When a 6-year-old boy was struck by a plow truck in his driveway in Greene on Wednesday, rescue workers and firefighters responded quickly to give medical aid.

But law enforcement officials are trying to sort out why state police were not dispatched for more than two hours.

Maine State Police Lt. Walter Grzyb said Thursday that no trooper was contacted until shortly before 9 a.m. about the 6:45 a.m. accident, which involved the boy on a scooter and his father, who was apparently backing up his truck.

Grzyb said Central Maine Medical Center notified the Maine Office of the Chief Medical Examiner, which alerted state police to ask whether they were investigating.

A trooper was sent to the hospital in Lewiston where the boy had been taken and a sergeant went to the boy’s home, Grzyb said.

“We were oblivious to it; we didn’t even know that it had occurred,” Grzyb said Thursday. “Obviously, we were quite concerned that, really, over two hours had passed before we were notified of this. We wanted to know why. Where did the ball get dropped?”

Had there been the need for a criminal investigation, the gathering and preservation of evidence or even someone to direct traffic, those services would have come hours too late, he said.

State police provide law enforcement coverage for the town of Greene every other month, alternating with the Androscoggin County Sheriff’s Office.

At some point, Grzyb said, state police dispatchers learned that an ambulance was sent to a home in Greene for an accident. What he doesn’t know, he said, is exactly what information was given to state police dispatchers and whether it signaled the need for a law enforcement response.

“They call us routinely for things we don’t need to respond to,” he said.

“If someone gets run over in a driveway, we’re going to respond to that immediately,” he said.

Capt. Ray Lafrance, who works in the Androscoggin County Sheriff’s Office, said Thursday that the county’s dispatch center called dispatchers at state police in Gray at 6:48 a.m when they got the 911 call reporting an auto versus pedestrian accident with injury at the home address in Greene.

Dispatchers called state police dispatchers again about two minutes later to update state police that a United Ambulance crew had arrived at the scene and that emergency workers were administering CPR, Lafrance said. County dispatchers also called the Lisbon dispatch center, which notified Greene Fire Department of the accident.

“Our dispatch center followed all protocols and calls went out within a minute,” Lafrance said. “So, I don’t know who dropped the ball, but it wasn’t us.”

Had state police told the county they didn’t have a trooper to respond, a sheriff’s deputy would have been dispatched to cover, Lafrance said.

Clifford Wells, director of the Consolidated Emergency Communications Bureau at the Maine Department of Public Safety, said Thursday that he had heard about the delay and was waiting to review the audio recordings of the calls from Androscoggin County dispatch center to the state police barracks supervisor in Gray.

That review would give him a “better handle on who knew what, when,” he said.