Resident With Knife Shot by Police; Officer Also Injured : Confrontation: Simi Valley man is wounded in the chest. A patrolman caught in the line of fire is not seriously hurt.

Police said they shot a mentally ill man Monday afternoon--and accidentally wounded one of their own officers--when the resident burst out of a bedroom holding a knife.

The gunshot wound to the unidentified officer’s right thigh was not severe, police said.

And Mark Pedersen--whom neighbors described as a gentle, friendly man except when his mental illness caused him to rave in a religious fervor outside his house--was shot in the chest. He was listed in serious condition Monday night at Simi Valley Hospital and was placed under arrest on suspicion of attempted murder.

Pedersen, a lanky 32-year-old with a recently shaven head, “had been out in the front yard screaming,” said Simi Valley Police Sgt. Bob Gardner. “And one of the neighbors called up.”

Elline Moberly made the call, just as neighbors had done several times before, as recently as November, according to police. He had been shouting religious slogans and blasting his radio, she said.

“I thought they’d just come and tell him to go back to his house, like they’d done before,” said Moberly, who has lived next door to the Pedersen family on Belgrave Court for 24 years. “He has not been mentally well for years and years and years. The whole neighborhood knows it.”

The police radio call held ironic echoes of a similar call last August that ended in the shooting death of Simi Valley Officer Michael Clark: Check the well-being of a disturbed man.

“When I came home, I saw Mark outside, acting a little strange and pacing back and forth and shouting things like ‘Praise Jesus’ and stuff like that,” said Mary Virzi, who lives across the street. “The police walked up, he saw them and ran in the house.”

Seeing Pedersen had gone inside, police radioed a dispatcher to phone the house.

His mother, Bea Pedersen, told the dispatcher that her son had locked himself in his bedroom and refused to come out. She warned the dispatcher that he had a mental condition and had not been taking his medication.

Bea Pedersen then let the two patrol officers and a supervisor inside so they could talk to her son.

She and police talked to her son through the bedroom door, but he refused to come out.

Then, police heard moaning sounds inside.

Fearing Pedersen might have hurt himself, they kicked open the door. Pedersen burst through the doorway carrying an open folding knife as if he were going to stab one of the officers, police said.

One of the officers then shot Pedersen once in the upper torso and fired again, accidentally hitting the colleague who had been attacked by Pedersen. The second bullet may have ricocheted before hitting the officer, police said.

Police then grabbed Pedersen and quickly summoned ambulances, which whisked both wounded men to the hospital.

Neighbor Luke Marquez was strolling outside the Pedersens’ house when he heard the shots.

“The windows were rattling, then we heard, like, two bangs,” said Luke, 16. “It sounded like someone was hammering something on a wall. Then we saw swarms of cops coming down the street.”

Dan Fritz, too, watched as paramedics carried out stretchers bearing first the officer, then Pedersen clad only in his underwear.

Dan, 14, grew up across the street from Pedersen.

Usually Pedersen was nice, Dan said. But when he would scream “Jehovah jiva!” and other seemingly religious slogans, word went around the neighborhood that Pedersen was off his medication again.

“He’d never been violent before,” Moberly said. “He would go up and tell people to repent and go to the Lord. He was always really peculiar. Today, he was very noisy all day long. He had his boombox blaring and he was saying, ‘Repent!’ When his mom pulled the plug to his boom box, that made him angry.”

Vivienne Tunba, a neighbor for about 20 years, said she noticed something different about Pedersen when he shaved his head recently.

But Tunba said Pedersen could be a helpful neighbor.

“When my parents were gone on vacation, he came to help me move the trash can to the street,” she said. “He’s a Christian boy, that I know. He’s quite religious.”

Reed is a Times staff writer. Brommer is a Times correspondent.