Homicide detectives appealed for help Tuesday to find a gunman they say killed a 55-year-old Minneapolis man, apparently in a dispute over a pack of cigarettes.

Robert Tousignant died after being confronted by an unknown man near the corner of 36th and Penn avenues N. in the Cleveland neighborhood sometime around 5 a.m. Tuesday. He was sitting in a parked car outside of the transitional house where he had lived for the past 2½ years.

He was identified Tuesday by residents of FreedomWorks, a Christian-based post-prison ministry that helps people transition to employment and permanent housing. Neighbors knew him as "Bob T."

According to a police spokesman, officers were dispatched about 5:48 a.m. to the parking lot of a house at the corner of 36th and Penn, where they found a man dead in a car. The victim and suspect appeared to have known one another, the spokesman said.

One of the home's residents, Antoine Powell, said he found Tousignant unconscious in the car and tried to revive him before realizing that he had been shot. Noticing that Tousignant's red sweater was soaked in blood, Powell said he ran inside and called 911.

Powell, who moved into the home two weeks ago, said he later watched footage from a security camera trained on the lot, which captured the entire episode.

In the grainy video, Tousignant is seen sitting in the driver's seat with the door ajar, smoking and playing games on his phone, as he did most mornings before going to work, according to Powell. A man in a hooded sweatshirt approached him, motioning with his hand as if he were asking for a cigarette, Powell said. Tousignant appears to tell him no — "Bob might've said something slick," Powell suspects — and the other man leaves but returns a few moments later and pulls out a chrome handgun from his waistband, Powell said. The gunman fired a single shot from point-blank range at the back of Tousignant's head, he said.

"Bob might've still been playing his game," Powell said. "He might not have seen him walk up."

Tousignant was pronounced dead at the scene. Police said officers spent the morning canvassing the neighborhood, looking for potential witnesses.

Tousignant had been determined to stay sober after bouts with alcohol and cocaine addiction, said George Lang, FreedomWorks' executive director.

"He'd reconciled with his family after years of drugging," Lang said of Tousignant, who worked as a construction laborer for a company in Savage. He left behind an adult daughter, Lang said.

Lang and Powell said they hoped the incident would call police attention to the drug traffic that has turned the parking lot of a nearby convenience store into a 24-hour drug market. Dealers as young as 14 peddle heroin, marijuana and prescription pills to eager buyers at all hours of the day, they said, which has turned the intersection into a magnet for violence.

"You so much as make eye contact and somebody thinks that you wanna hook up, and you need dope, or you're looking for trouble," Lang said.

By midday Tuesday, an impromptu memorial of flowers and balloons was wrapped around a tree across the street from the house. As of Tuesday afternoon, no arrests had been made in the slaying, the city's 24th of the year.

Tuesday's shooting happened fewer than two blocks away from the scene of another homicide last fall, in which a 46-year-old woman was shot in her car. Relatives said Dana Logan had just dropped off her grandniece near 36th and Queen avenues N. when she was caught in crossfire from rival gunmen. She later died at a nearby hospital