A Massachusetts State Police trooper was stabbed and the suspect — an 18-year-old Melrose man — was shot in an altercation alongside Interstate 495 in Amesbury Thursday, according to authorities.

State police and Amesbury police responded just after noon to a “chilling radio transmission” from the trooper requesting assistance on the highway’s southbound side, prior to Exit 54, Col. Christopher Mason, superintendent of the state police, told reporters.

There, responders found the 34-year-old trooper suffering from stab wounds to his left arm, Mason said during a press conference. The suspect, identified as Nathan Aguilar, was on the ground, he said.

The trooper, a member of the department for three-and-a-half years and a military veteran, was brought to Lawrence General Hospital and later released, Mason said. His name has not been disclosed.


Aguilar was brought to Anna Jaques Hospital in Newburyport and later flown to Beth Israel Deaconess Medical Center in Boston for treatment, he said.

A preliminary investigation found Aguilar was driving a minivan on I-495 before he entered the breakdown lane near where crews were working on highway signage, according to Mason.

Aguilar allegedly exited his van and approached the work site where the trooper, assigned on a public safety detail, was inside a cruiser, police said.

Aguilar produced a knife when he arrived at the driver’s side door of the vehicle, Mason said.

A violent struggle then ensued between the two men, which injured the trooper, who Mason said “was forced to discharge his service weapon,” causing Aguilar “to fall to the ground.”

Authorities are still investigating a motive for the alleged attack. Mason said there is no evidence of any relation between the trooper and Aguilar.

He could not immediately say how many shots were fired or how exactly the confrontation played out.

“We’re no stranger to attacks by people with edged weapons and we understand and appreciate how dangerous they can be, which gives us a great appreciation for how bad this could have gone today,” Mason said. “And we’re very grateful that I’m not standing here making a different kind of statement.”


The two right lanes on I-495 south were closed Thursday afternoon as police investigated the scene.