A Rhode Island man who allegedly blew through a checkpoint at Camp Edwards in Bourne early Monday before crashing into a pole and later fighting with police was a former high school football star whose life had spiraled out of control, his grandmother said.

Around 1:40 a.m. Monday, police say, Harold Lamotte, 31, of Charlestown, failed to stop at the gate that leads onto Joint Base Cape Cod, home to Otis Air National Guard Base and Camp Edwards. He sped away and soon hit a utility pole on Estey Road.

When Air Force security and State Police took the man into custody and began the booking process at the barracks in Bourne, he allegedly became combative and tried to escape, officials said.

Lamotte now faces nine charges, including assault and battery on a police officer, resisting arrest, trespassing, and attempting to escape from jail, as well as several traffic violations, according to State Police.

“There are times he doesn’t know what he’s doing,’’ said Lamotte’s grandmother, who asked that her name not be published because of the sensitivity of the situation. Her grandson, she said, had been in and out of treatment for mental illness in recent years. She said he had lost his job as a correctional officer in Rhode Island.

Police are investigating why Lamotte allegedly drove through the Bourne gate, one entrance to Joint Base Cape Cod. But State Police spokesman Dave Procopio said in a news release that there is no indication that Lamotte is a threat to national security or is connected to terrorism in any way.

Lamotte’s grandmother said she did not learn of the incident until she awoke Monday morning to find her 1998 Volvo missing and Lamotte’s car in the driveway out of gas.

“This was nothing that was done to hurt anyone or anything like that,’’ she said. “He didn’t know what he was doing and he had an accident.’’

Lamotte’s grandmother said he starred on the football field for Westerly High School, and wondered whether a history of concussions contributed to his erratic behavior.

News reports at the time show Lamotte, known then as J.R., led Westerly to two state Division II championships and was named in 2006 to Rhode Island All-Star Football’s all-time team. Online records indicate he went on to play at the University of Rhode Island.

“He’s having a lot of anxiety problems,’’ and the only person he would try to hurt was himself, his grandmother said.

Bail for Lamotte, who is being held at Charlestown House of Correction, was set at $25,000. He is scheduled to be arraigned Tuesday.

Nestor Ramos can be reached at nestor.ramos@globe.com. Follow him on Twitter @NestorARamos.