REDWOOD CITY -- Milo Imrie of Richmond was a Marine in Afghanistan during a recent deployment when he walked past something he thought looked suspicious. Moments later a colleague stepped on the device -- it was an explosive -- and was killed, his attorney said.

That incident sowed the seeds for a violent confrontation with Sheriff's deputies in Woodside that now has prosecutors seeking to increase his $25,000 bail, defense attorney Geoff Carr said Tuesday.

Imrie, 23, is due back in San Mateo County Superior Court on Wednesday.

Prosecutors said the trouble started Dec. 12 when Imrie was at his 22-year-old cousin's house in Woodside and allegedly threatened to douse himself and the cousin with gasoline

and then spark a fire. He also threatened to use a knife, officials said.

The cousin yanked the gas can away from Imrie and then grabbed some kitchen knives and tossed them onto the roof, prosecutors said. But when the cousin's back was turned, Imrie allegedly clubbed him with a shovel.

Both men ran away and deputies later shocked Imrie with a Taser and arrested him, authorities said. One deputy noted he had a "thousand yard stare."

Imrie now faces one felony count each of assault with a deadly weapon and resisting arrest, which stems from an attempt to snatch a handgun from one of the deputies, prosecutors said. He remains behind bars.

After reading the police reports and visiting his client in jail, Carr said he

immediately knew the source of the trouble.

"It's classic post-traumatic stress disorder," said Carr, a Vietnam War veteran.

Carr has since learned that Imrie was deployed in Afghanistan recently and was on patrol when he walked past something that caught his eye. Imrie was part of a unit that disarmed improvised explosive devices. He made a split-second decision not to check out his hunch and moments later an Afghan interpreter stepped on the device, setting off an explosive that killed him.

"It's about guilt," Carr said. "Just for having thought about it, he blames himself."

Imrie's been back in the United States for at least a year and things have not been going well, Carr said. He was in school, but that was not working out. He'd been drinking too much and had sought counseling from Veterans Affairs. But what finally sent him over the edge is unclear, Carr said.

Chief Deputy District Attorney Karen Guidotti said her office is aware of Imrie's claim that he has mental health issues, but added he faces hefty charges.

"Unfortunately there is some serious violence here that needs to be addressed," she said.

Contact Joshua Melvin at 650-348-4335. Follow him at Twitter.com/melvinreport.