William Senne, 29, of Wayland, on Wednesday pleaded guilty to motor vehicle homicide and was sentenced to three years probation as the result of a 2003 Wareham drunk-driving crash that took the life of a state trooper.

Senne, 18 at the time of the accident, had pleaded guilty in 2005 to charges of operating under the influence to cause serious bodily injury and was sentenced to 2.5 years in prison. He was released in 2007.

The vehicular homicide charge was added after Trooper Ellen Engelhardt succombed to her injuries in June of 2011 at the age of 58.

In 2003, Engelhardt's cruiser was stopped in the breakdown lane on Route 25 when it was rear-ended by a vehicle driven by Senne. Engelhardt suffered a severe brain injury that ultimately took her life.

“We hope, most of all, that the Engelhardt family finds solace in their warm memories of Ellen and in the stellar regard with which her memory is held throughout the Massachusetts State Police,” said Timothy Alben, Massachusetts State Police colonel. “Her sacrifice in the line of duty will forever be in our minds, and we will always grieve for her loss.”

On Jan. 29, Senne was sentenced to three years probation and 500 hours of community service at a brain-injury-related facility and lost his license for 15 years.

“We wanted him to serve four to five years in prison,” said Plymouth County District Attorney Timothy Cruz. “We had requested more time with his poor driving record.”

Cruz said on July 3, 2008, Senne was caught speeding in the Wareham/Middleboro area.

“He hasn’t learned,” Cruz added.

“We appreciate the efforts of District Attorney Cruz and his staff to speak for Trooper Engelhardt and hold the defendant accountable under the law. That said, we respect the judicial process,” Alben said.