Jurors in a Little Canada man's murder trial will have to decide whether he acted with murderous intent or in self-defense when he allegedly pushed another man into oncoming traffic in August, killing him.

Assistant Ramsey County Attorney Rachel Kraker told jurors Tuesday that Michael J. Merten III murdered Robert Hilgren, shoving him with "two hands, arms extended, full force." Kraker and Merten's attorney, Bruce Rivers, gave jurors different accounts of the Aug. 20 incident in opening statements Tuesday.

Kraker said Merten, 41, had confronted Hilgren's 23-year-old son, Preston Hilgren, and then pushed the elder Hilgren, 47, when he responded to his son's call for help.

Rivers told jurors Merten was trying to flee from the two "self-professed brawler" Hilgrens. Robert Hilgren wouldn't relent, Rivers said, following Merten into the middle of Rice Street near County Road B2 and preparing to throw a punch when he fell into traffic as Merten defended himself.

"This is a case of self-defense," Rivers said. "There will be no evidence in this case to show that my client was the aggressor."

Authorities allege in two counts of second-degree murder that Robert Hilgren and his wife received a call from their son "screaming that a 'big, crazy dude' " was chasing him and trying to beat him up. The family had been in the area celebrating Preston Hilgren's birthday. The couple were driving when they saw Merten allegedly chasing their son.

That's when Robert Hilgren got out of the car and joined the quarrel, confronting Merten and telling him, "You want a piece of me? You want to throw down with me?"

The men bumped chests, and witnesses said Merten shoved Robert Hilgren at least three times. Hilgren's wife told police that Merten waited for a car to approach before pushing her husband into its path about 9:10 p.m.

Kraker told jurors that witnesses would testify that Merten shoved Hilgren. She also warned them that the Hilgrens had been drinking, and that Preston Hilgren had also used meth that day.

"Not every story is exactly the same," she said.

Rivers told jurors that Merten was trying to go to his home in a nearby mobile home park when Robert Hilgren placed himself between Merten and the park.

"Mr. Hilgren closed the gap," he said. "[Merten] had nowhere to go."

Rivers noted that Merten went home after the incident, waited for police to arrive and cooperated with the investigation.

One witness, whose account is documented in a 911 call, described the Hilgrens' pursuit of Merten.

"… two guys were kinda picking a fight with another guy and he's yelling I live here and ah, they were chasing him down, he was trying to get away from them in the middle of Rice Street, trying to stop cars to get them to help him or get these guys away from him," the 911 transcript read. "And then they kinda went away and then he was standing in the middle of the street and one guy of the two approached him in the middle of the street."

Testimony began Tuesday with the account of Gregory Barnes, who drove the car that struck Hilgren. Barnes testified that he was leaving work when he saw one man push another man into his path. Barnes said he didn't have time to swerve or brake, and that he wouldn't be able to identify either man, noting that he was "traumatized" by the incident.

"It's a troubling thing that happened around me, to me," he said quietly.

Testimony is scheduled to resume Wednesday morning.

Chao Xiong • 612-270-4708

Twitter: @ChaoStrib