CHARLTON (CBS) — A 30-year-old Webster man has been charged following a crash on the Massachusetts Turnpike in Charlton on Wednesday afternoon that claimed the life of a State Trooper.

Read: State Police, Hudson Mourn Loss Of Trooper Thomas Clardy

READ MORE: New Memorial In Worcester Honors Firefighters Killed In Line Of Duty

David Njuguna was served with a summons charging him with negligent operation of a motor vehicle and failure to stay within marked lanes. His right to operate a motor vehicle has been revoked due to an immediate threat notification filed by State Police to the RMV, investigators say.

David Njuguna. (Facebook photo)

David Njuguna (Facebook photo)

Njuguna told his family he blacked out when he crashed into Massachusetts State Trooper Thomas Clardy‘s cruiser, killing him.

The Nissan Maxima after the crash. (WBZ-TV)

The Nissan Maxima after the crash. (WBZ-TV)

The 44-year-old trooper was a U.S. Marine Corps veteran and had joined State Police in April 2005.

State Trooper Thomas Clardy. (Photo credit: Mass. State Police)

State Trooper Thomas Clardy. (Photo credit: Mass. State Police)

“He doesn’t remember anything,” said Njuguna’s sister-in-law, who declined to be identified, adding that she visited him at UMass Memorial Medical Center. She told WBZ he was confused, as he’s recovering from a concussion.

“We’re still in shock, and we’re so sorry about the trooper’s family,” she said.

READ MORE: 2 Extricated From Car After Crash In Medford

Investigators are focused on what caused Njuguna to suddenly swerve from the left, cross three lanes on the Mass Pike and crash into Clardy’s SUV on the right shoulder, where he’d pulled over another driver.

The State Police SUV after the crash. (WBZ-TV)

The State Police SUV after the crash. (WBZ-TV)

Robert Doucette, Njuguna’s neighbor, says Njuguna could rarely be seen at home.

“He works a lot of hours. I think he fell asleep,” he told WBZ-TV on Thursday. “I barely see his car here and if it is, it’s late at night and then it’s gone in the morning.”

On Facebook one day earlier, Njuguna posted, ” Couldn’t get enough sleep. Even my medication is not working.”

His record shows he’s had an accident before, and a suspended license for refusing to take a breathalyzer two-and-a-half years ago. But neighbors say they never would’ve expected this.

“I heard that he got killed and I’m very saddened by that,” said Njuguna’s neighbor, Erick Toussaint. “It’s awful.”

The crash remains under investigation by police.

MORE NEWS: 'Loss Of A Beautiful Boy': Candlelight Vigil Held In Memory Of 5-Year-Old Elijah Lewis

As of Thursday night, Njuguna was in stable condition at the medical center. He is expected to be arraigned at some point soon in Dudley District Court.

Christina Hager