Man killed by police after slaying San Jose police officer obsessed with ISIS

SAN JOSE, Calif. -- A police officer who fatally shot an armed man who suffered from mental illness and killed a fellow officer last year in East San Jose was "lawfully justified" in his actions, Santa Clara County prosecutors said today.

Scott Irwin Dunham, 57, had fired a rifle from his apartment balcony near Senter and Tully roads, where he struck Officer Michael Johnson on the evening of March 24, 2015.

The investigation revealed that Dunham had been obsessed with ISIS, threatened to decapitate his wife, had a history of spousal abuse and was bipolar and schizophrenic.

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Johnson, 38, was killed at the scene and Officer Douglas Potwora fired back at the armed suspect, who died from a bullet wound to the head according to the district attorney's office.

"Dunham appeared not only determined to die at the hands of the police that evening, but equally determined to first take as many police officers' lives as he could," Deputy District Attorney Carolyn Powell said in a 47-page report released today on the office's investigation.

Officers had responded to the Senterville Terrace condominium complex just before 7 p.m. that day on a report of an intoxicated and armed man who made threats to take his own life, Powell said.

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Johnson squatted down from behind a vehicle and aimed his weapon toward the balcony while Potwora and another officer reached the scene, according to Powell.

As Johnson was briefing Potwora on the incident, Dunham showed up at the balcony, where he didn't comply with orders to show his hands, ducked down and fired shots, Powell said.

Johnson was fatally hit by one bullet and Potwora fired back at Dunham, who ducked down twice, according to the report.

When Dunham went over the balcony railing, Potwora fired one shot that hit the suspect's head, Powell said.

Hours later when officers determined the scene was safe, they went inside Dunham's apartment and found him dead next to a loaded and cocked .30-30 rifle, according to Powell.

A search of the apartment uncovered two additional guns and hundreds of bullets, she said.

An autopsy by the Santa Clara County medical examiner's office showed Dunham had a near toxic combination of medication and alcohol in his system, the report said.

Investigators looked into Dunham's history, which showed he was unemployed and had a history with domestic violence, suicidal tendencies and mental illness, according to Powell.

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Potwora had 17 years of experience with San Jose police at the time of the shooting and has specialized training in responding to high-risk situations, Powell said.

Johnson had worked 14 years with the Police Department and was its 12th officer killed in the line of duty. A segment of state Highway 87 was dedicated to him on the anniversary of his death earlier this year.