HILLSBORO, Ore. -- A suspect was shot and killed by a Hillsboro police officer after hijacking a helicopter and firing a gun at the Hillsboro airport on Monday morning, police said.

On Thursday, the Hillsboro Police Department identified Melvin Ambrose, a 27-year veteran of the department, as the officer involved in the shooting.

Ambrose is on paid administrative leave while the shooting is under investigation by the Washington County Major Crimes Team. Once they have finished their investigation, it will go to the Washington County District Attorney for review.

The autopsy on the suspect, identified Wednesday as 25-year-old Holden Gorka of Olympia, was completed Tuesday. Officials said the toxicology report will take 60-90 days to complete.

At this time, there is no evidence that Gorka had a history of mental health issues or substance abuse, but Hillsboro police Lt. Henry Reimann said that could change as the investigation unfolds.

Reimann also said investigators have not discovered any connection between Gorka and the Hillsboro Aero Academy. His motive for trying to steal the helicopter is unknown at this time.

The Hillsboro airport, where a person tried to steal a helicopter Monday, July 3, 2017. (Photo: Pat Dooris, KGW)

According to authorities, Gorka jumped a fence at the Hillsboro Airport at about 11:36 a.m. Monday and ordered a man and woman to get out of the helicopter, firing a shot from his gun in the process. The two people got out of the helicopter at that point and Gorka climbed in.

Several employees from Hillsboro Aero Air held Gorka at gunpoint while he sat in the helicopter until the first officer, Ambrose, arrived at 11:39 a.m. When he saw Ambrose, Gorka got out of the helicopter and ran, climbing over the fence and running across the road to a field.

Ambrose confronted Gorka in the field and shot him. Gorka died at the scene shortly before noon. No other injuries were reported.

The suspect who fired shots at the Hillsboro airport after trying to steal a helicopter on Monday, July 3, 2017, is dead, police confirmed. (Photo: Pat Dooris, KGW)

A witness, Christopher Neal, told reporters that he and his family were watching planes at the small airport when he saw a man walking in wearing a gray hoodie. The man looked at them and then started running toward the fence. He pulled a gray mask over his face, Neal said.

The Port of Portland released a statement thanking the Hillsboro Police Department.

"The Port of Portland is grateful for the quick and professional response of the Hillsboro police department. The Hillsboro police are leading the investigation into the incident. The Hillsboro airport has resumed airport operations," the statement read.

The Associated Press contributed to this article.