A state trooper is being charged with drunken driving in a head-on collision in Plymouth that killed a Carver mother and daughter last Sunday, Plymouth police said today.

The trooper, 25-year-old John J. Basler, of Kingston, will be charged with operating a vehicle under the influence of alcohol, negligent operation of a motor vehicle, and carrying a firearm while under the influence of liquor, according to Plymouth police.

Basler, who was sworn in as a state trooper in March 2012, was not on duty at the time of the crash, said State Police spokesman David Procopio in a statement.

State Police have temporarily relieved Basler of duty and have revoked his license to carry a firearm, Procopio said.


Chief Michael Botieri of Plymouth Police said it was particularly disturbing to learn through the course of the accident investigation that the tragedy appeared to be caused by a law enforcement officer.

“It’s very difficult,’’ Botieri said, “but none of these kinds of investigations are easy.’’

The head-on collision occurred just after midnight last Sunday morning on Federal Furnace Road. The driver of one of the cars was 64-year-old Susan Macchi of Carver, who was pronounced dead at the scene. In the passenger seat was her 23-year-old daughter, Juliet Macchi, who died later at Jordan Hospital in Plymouth.

Basler was taken to South Shore Hospital in Weymouth, where he was in stable condition.

Initially, police said they did not believe alcohol or speed were factors in the crash.

Basler, who had been assigned to the State Police barracks in Milton, will be asked to appear at a duty status hearing early this week, where it will be determined whether he will be suspended while the criminal charges are prosecuted.

As police continue to investigate the crash, additional charges could be brought against him, Botieri said.