A young woman is killed in her home, felled by a shotgun blast to the back of the head. Her husband's thigh is wounded from another gunshot blast. Police suspect the man killed his wife, and that his wound was self-inflicted, part of a coverup story about an interrupted burglary. The husband says he didn't do it.

When defendants face such a situation, their lawyers often call Michael Grostyan. The veteran private investigator, a former St. Paul cop, spends most of his billable hours grinding away at charges brought by police and prosecutors. Grostyan reinvestigates step-by-step. He revisits crime scenes and interviews witnesses, searching for the hole or the hitch in the police narrative, the forgotten detail or the ignored eyewitness.

For more than 30 years, Grostyan has narrowed his duties. He used to serve papers to legal defendants, a mundane but well-paid gig he dropped after one recipient held a knife to his throat. As for the classic case of a woman who suspects her man is stepping out, these days Grostyan fields only a few each year.

"Many times these women get done with their story and I think to myself, 'Do you really think you need me, after everything you've told me?'" Grostyan said.

Grostyan eschews the typical detective affectations. His glasses are prescription, not pitch-black Ray-Bans. He drives a Mercedes sedan, dresses in a suit and tie, and speaks without the clichés of hardboiled pulp fiction. His professionalism sets him apart, but comes at a price -- $100 an hour, to be exact.

Grostyan's defense cases include homicides, assaults and criminal sexual conduct. He's at peace with the role. Everyone deserves an adequate legal defense, Grostyan said, and he won't ignore facts or lie to help a client's defense.

At least 30 percent of the time, he tells a defense lawyer that the police have an airtight case. But on others, like the story of the St. Paul man being investigated in his wife's death -- who remains a suspect but hasn't been charged -- Grostyan becomes convinced he is investigating an innocent man. He said police are often understaffed and, perhaps more important, under pressure to produce a suspect. But he's under pressure, too.

"I've worked on hundreds of murders over the years," he said. "People are [facing] going away for the rest of their life. Those stakes are high. And I don't take my responsibility lightly."

MICHAEL GROSTYAN

Age: 65. Job title: Private investigator. Employer: Self- employed. Start date: 1981. Education: University of Minnesota criminal justice major.