A Vancouver police officer sat in the passenger seat of a speeding police car and used the dashboard to stabilize his AR-15 rifle as he shot through the front windshield at a fleeing truck carrying a suspected killer, spraying more than 40 rounds over several miles on Portland freeways.

The new details of the wild shootout that closed both Interstate 205 and Interstate 84 for hours Feb. 5 comes from officers familiar with the encounter.

The Vancouver officer, James Porter, began firing after someone in the pickup shot at his partner and him as they gave chase across the Washington border into Oregon, heading south on Interstate 205. Porter was serving as a field training officer that night, instructing a recruit, who had been on the job for less than a year. The recruit was behind the driver’s wheel.

The chase hit speeds of up to 110 mph, according to sources familiar with the case but not authorized to talk about it publicly.

Firing through the windshield would initially shatter glass and deflect the first bullets but then most likely would bore a hole through the glass that would create an opening that after a few rounds would allow subsequent bullets to fly pretty straight, experts said.

The shootout between an occupant in the fleeing suspect’s truck and the Vancouver officer spanned more than six miles, as the truck turned west onto I-84 from I-205.

Porter’s car pulled over after it appeared Porter was hit in the face by flying debris. Other Vancouver police continued the chase.

Vancouver police performed a Pursuit Intervention Technique, or so-called PIT maneuver, to stop the dark pickup, ramming into a side of the truck with a police car on westbound I-84, near the Lloyd Center exit. One of the pickup’s occupants was ejected onto the road, and the pickup came to a rest against a concrete barrier along the shoulder of the westbound freeway lanes, its tires flattened.

Vancouver police were trying to arrest wanted suspect Erkinson K. Bossy, 23. Police say Bossy was involved in the Jan. 22 fatal shooting of a convenience store clerk in Kelso.

The officers were concerned that allowing the truck to get off the freeway could lead to the taking of a hostage or another violent situation, the sources said.

Under Vancouver police policy, an officer should fire at a moving vehicle or the people inside only when the officer “reasonably believes there are no other means available to avert the threat of the vehicle,’’ said Vancouver police spokeswoman Kim Kapp.

Portland police are leading the investigation of the shooting. Investigators found more than 40 casings from Porter’s rifle inside the Vancouver police car.

It’s unclear if Bossy or another man in the pickup was shooting at police or how many times.

Porter, 28, was treated and released from Legacy Emanuel Medical Center the night of the shooting. He returned to patrol work on Feb. 21, Kapp said. Vancouver will do an independent investigation through its Professional Standards Division, she said.

The occupant of the pickup who was ejected suffered life-threatening injuries but was later said to be in stable condition at a local hospital. The other occupant was treated at a hospital for injuries that weren’t serious. Police did not disclose the nature of Bossy’s injuries, and still have not identified the second occupant of the truck.

Portland police spokeswoman Lt. Tina Jones said Thursday that the Multnomah County District Attorney’s Office is reviewing the Portland police investigation.

The prosecutors’ office is waiting for the bureau’s report and hasn’t yet decided whether to present the case to a grand jury for review, according to Brent Weisberg, the office spokesman.

Grand juries typically review cases when a shooting by a police officer injures or kills someone, though the district attorney has discretion to determine that a review isn’t warranted, according to the office policy.

The Vancouver officer’s shots didn’t appear to wound Bossy. It’s unclear if they hit anyone in the fleeing truck. Investigators haven’t indicated who was driving, or the name of another man who was in the truck at the time.

No one has been charged yet with shooting at Vancouver police.

Bossy remains in custody in Multnomah County on a fugitive warrant. He’s wanted in Cowlitz County on charges of first-degree murder, first-degree robbery and unlawful possession of a gun, court records indicate.

Two out-of-state police firearms trainers told The Oregonian/OregonLive that the tactics used by Vancouver police are warranted only in extreme circumstances.

An officer would have to consider the “totality of circumstances,’’ taking into account the traffic in the area, the officer’s line of sight and who’s in the fleeing car, said Massad Ayoob, a Florida-based police firearms instructor who served for 19 years as chair of the Firearms Committee of the American Society of Law Enforcement Trainers.

When someone is shooting at police, that might require “drastic measures,’’ to stop the threat, he said.

“Anyone who will shoot at a cop is dangerous enough to shoot at anybody. If the officer is under fire or he perceives the vehicle he’s pursuing is in imminent danger of causing injury to others, he’d be justified in shooting back,’’ Ayoob said.

Retired Minnesota officer David Kisch called the encounter a “no-win situation.’’

The officer’s duty is to stop the threat, said Kisch, who provides active shooter training to police.

“When you’ve got people shooting at you when you’re a cop, things have already gotten really bad,” he said. “As a police officer, you have to account for every bullet.”

-- Maxine Bernstein

Email at mbernstein@oregonian.com

Follow on Twitter @maxoregonian

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