A Massachusetts State Police trooper suffered stab and slash wounds and a suspect was shot during an altercation on an interstate highway Thursday, agency commander Col. Christopher Mason said.
The trooper was treated and released from the hospital after the confrontation on Interstate 495 south in Amesbury early Thursday afternoon.
The trooper's name was not released, but he was described as 34 years of age, a military veteran and a 3 1/2-year veteran of the force.
The suspect was identified by Mason as Nathan Aguilar, 18, of Melrose.
He was flown to a Boston hospital for treatment. His condition was not given.
The trooper was working a detail, protecting a sign replacement crew, Mason said, when Aguilar pulled up and the altercation ensued.
The case remains under investigation.