St. Paul police said Tuesday that their investigation continues after a 24-year-old man being robbed at gunpoint pulled a gun and shot one of his assailants Monday.

The would-be victim was not injured, and police Tuesday identified Joseph Barre, 29, as the suspect who’d been shot in the foot.

Police were called to the Hmongtown Marketplace at Como and Pennsylvania avenues about 5:30 p.m. Monday with a report of shots fired, and officers recovered several casings, according to a police report. A St. Paul man had been walking outside when two men approached and tried to rob him, police have said.

The man, who had a permit to carry, pulled his gun and exchanged gunfire with the suspects, according to police.

Lowell Schoenherr was at a park across the street when he heard three shots, turned around and saw a man who hobbled away and got into the back of a car. A car pulled behind it and both drove off quickly, said Schoenherr. He didn’t see what led to the incident and he was surprised to hear the shots, he said.

Police have said the 24-year-old man got into his own car and pursued the suspects. A second gunfight followed in the 900 block of Thomas Avenue.

The 24-year-old returned to the scene of the first incident and spoke with police, and Barre later showed up at Regions Hospital with the gunshot wound to his foot. A relative of Barre’s declined comment. Police said Tuesday afternoon they were continuing to look for the second suspect.

Police had not presented a case Tuesday to the Ramsey County attorney’s office to review for charges.

The case is “very complex” with “multiple crime scenes,” said Sgt. Paul Paulos, a St. Paul police spokesman. He said the investigation includes determining how many shots were fired and whether the victim and suspects knew one another.

Minnesota courts have set a four-part test to determine whether the use of deadly force is justified under self-defense, said Andrew Rothman, Gun Owners Civil Rights Alliance president. The factors are: Was the person in immediate fear of death or great bodily harm, and was that belief reasonable? Would no lesser force have served to end the threat? Was retreat not practical? And, was the person the “non-aggressor” in the initial encounter?

It’s not unlawful for someone to follow suspects, Rothman said, adding that he’d need more information about what happened in the St. Paul case to assess the second part of the incident.

“At some point, if they (the suspects) initiated a second encounter, he may have again been in a situation where he was authorized by the law to use deadly force,” Rothman said.

Mara H. Gottfried can be reached at 651-228-5262. Follow her at twitter.com/MaraGottfried.