CHICOPEE — A Massachusetts State Police trooper has been charged with drunken driving and other offenses following a crash that left at least one person seriously injured.

A criminal complaint was issued Friday in Chicopee District Court against Trooper Jason M. Welch, 35, charging him with operating under the influence of liquor causing serious injury, reckless operation of a motor vehicle, operating under the influence of liquor and failure to take care in stopping.

The charges were filed following a state police investigation into the July 21 crash, said state police spokesman David Procopio.

While police did not reveal the name of the trooper, saying it was against policy to release names of defendants until they are formally charged, court records included Welch’s name and the charges.

Welch is scheduled to be arraigned on Sept. 5. Court officials could not say why the arraignment was delayed and police did not explain why he will not be arraigned for a month.

Welch is charged in connection to a crash that occurred at 2:44 a.m., on Interstate 291, which is also Burnett Road, at the intersection of Johnny Cake Hollow near the Exit 6 interchange. He was off duty and driving his personal vehicle, a 2012 Ford F-150 pickup truck, Procopio said.

Welch is accused of striking a 2007 Ford Expedition that was occupied by a man and a woman, he said.

The passenger in the Expedition, a 34-year-old man, suffered serious injuries and was taken by ambulance to Baystate Medical Center in Springfield.

Welch and his passenger were also transported to Baystate with injuries, Procopio said. The passenger is listed as being on active duty, but it was unclear if he was out due to injuries, Procopio said.

The driver of the Expedition, a 33-year-old woman, sustained minor injuries.

According to the Chicopee police, log a caller reported a rear-end collision on Burnett Road. The dispatcher state troopers and local police to respond.

A Chicopee police officer was the first to arrive at 2:49 a.m. and two other officers responded shortly after. State police arrived later and at 3:15 a.m. they took over the crash investigation, the log said.

Chicopee police public information officer Michael Wilk confirmed local police responded but had little involvement with the crash because troopers determined it occurred on a state highway.

Welch was initially placed on restricted duty, and has not yet returned to work. Because of the pending criminal charges, an Internal Affairs case was opened due to the state police investigation, Procopio said.

“The Department will hold another hearing for that member (Welch) and expects to further amend his duty status,” Procopio said. "That amended status will remain in effect for the duration of the judicial proceedings, following which his status will be re-evaluated based on the results of those proceedings and the separate Internal Affairs investigation.”

State police records show Welch, an Ayer native, graduated from the State Police Academy in 2014. He works for Troop B, which has seven barracks in Western Massachusetts including those in Northampton, Springfield and Westfield.