A St. Paul man charged with fatally shooting a law clerk testified Tuesday that he was fed up with his attorney and frustrated that the clerk couldn't track him down.

Ryan D. Petersen testified that he drove from his business on St. Paul's East Side to North Star Criminal Defense in the Cathedral Hill neighborhood on April 7 in order to fire his attorney, Dan Adkins, and recoup some of the $7,000 he had paid.

But 23-year-old Chase Passauer was the only person in the office.

"By [Adkins] not being there, my head exploded," Petersen testified. "It was an emotional explosion, and I fired the gun …"

Passauer was shot eight times.

Petersen, 37, opted to be tried in front of Ramsey County District Judge William Leary instead of a jury on one count each of first-degree premeditated murder, second-degree murder with intent and illegal possession of a firearm.

He rambled at times as he explained how stress in his relationships and problems with his business contributed to his state of mind that day. He also shed tears throughout the two-hour testimony, and twice solicited laughs from viewers in the courtroom, a nod to alleged inconsistencies that Assistant Ramsey County Attorney Rick Dusterhoft tried to highlight in his cross-examination.

Petersen's attorneys, Gary Wolf and Holly Frame, attempted to cast him as a caring father whose personal troubles began mounting after his father's death in July 2015.

A longtime friend, Aaron Ellering, and Petersen's sister, Heather Imamovic, testified that although Petersen always had a temper and poor coping skills, his mental health showed dramatic deterioration starting in January.

He was drinking heavily, smoking cigarettes, using cocaine and hanging out with old friends in favor of his previous focus on bodybuilding, healthy eating and spending time with family, they said.

Imamovic said Petersen had problems with his girlfriend and the mother of his children. Also, he was on poor terms with a tattoo shop located next to his business, East Side Gold Grillz, and was experiencing issues with a business supplier.

Petersen testified that he was born at the Mayo Clinic in Rochester while his birth mother was institutionalized for being a paranoid schizophrenic, and that he was placed for adoption at 5 days old.

Petersen said that on the day Passauer was killed, he was upset that an employee at the tattoo shop was allowed to park in a spot he had previously been told was off-limits, so he tried to reach Adkins for help.

Adkins was dismissive, he said, and generally unresponsive. He said Adkins told him to meet him at the law firm around 4 p.m.

Adkins testified Tuesday that he did not schedule a meeting, and told Petersen he was in court in Stillwater.

Under questioning by Wolf, Petersen said he never intended to shoot anyone, and that despite previous felony convictions, he carried a gun for protection because his business caters to customers with criminal backgrounds.

Petersen said that Passauer was "argumentative." He testified that he fired the gun at close range with his eyes closed at some point, and didn't even know he had struck Passauer until someone later sent him news about the shooting as he fled.

Under questioning by Dusterhoft, Petersen testified that Passauer said he didn't know where Adkins was and couldn't reach him. Dusterhoft asked how that was "argumentative."

"It wasn't the response I was looking for, I guess," Petersen said.

Several people in the courtroom laughed loudly in apparent disbelief.

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