So when those who knew him heard the 34-year-old homeless man had been fatally shot by Montreal police following an altercation, the news hit a nerve.
Mohammadi's death is the second time in less than a year that a homeless man has been killed by Montreal police.
Last June, a homeless man wielding a knife was shot and killed on a downtown street. An innocent bystander was also struck and killed during that incident.
The latest fatality has shone a light on the often difficult relationship between police and the city's homeless.
Matthew Pearce, director general of Montreal's Old Brewery Mission shelter where Mohammadi once stayed, described it as "not an easy and comfortable one."
"Typically, the police are the ones who are moving (the homeless) on from where they are," he said in a phone interview.
"A large percentage of the homeless population suffers from mental illnesses. Consequently, they become more unpredictable in a situation where the tensions rise."
At a soup kitchen Mohammadi used to frequent, several men and women who lined up for lunch on Sunday expressed their anger and frustration that the altercation involving Mohammadi ended in his death.
Andre, a homeless man who declined to give his last name, said some police officers, particularly young recruits, don't know how to deal with people living on the street.
Some of the more seasoned officers are better trained, but there aren't enough of them, he said.
Andre, who was forced out of his apartment and now lives in his truck, said Mohammadi was of Iranian descent and spoke a little French and English.
"He was curt," said Andre. "He wouldn't talk to you if he didn't know you...but I never saw him doing anything violent."
Mohammadi died on Friday afternoon after an altercation with two officers in a downtown subway station.
One of the officers was treated for knife cuts to the head and upper body, and the other for shock. Both were released from hospital late Friday.
Details of the incident remain unclear.
Quebec provincial police have taken over the investigation, but offered little new information on Sunday.
Witnesses have said they saw one officer pull a gun and the other a nightstick as they ordered Mohammadi to stop inside the subway.
Mohammadi began to run and when he turned a corner, at least three gunshots were fired, according to witnesses.
Mohammadi wasn't carrying identification on Friday and had to be identified with his fingerprints.
Jean-Francois Peterka, a volunteer at Accueil Bonneau, a soup kitchen in Old Montreal, described Mohammadi as a loner who appeared to suffer from mental illness.
"He was a solitary guy," said Peterka, who himself lived on the street for two years and now lives in a half-way house.
"He often spoke to himself, and he never really fit in with the crowd."
Reports suggest Mohammadi had bounced around the city's shelters since at least 2009.
Pearce said he last stayed in the Old Brewery Mission in that year. Mohammadi was briefly suspended from the shelter because of an incident "that probably involved some aggression on his part towards a staff person," Pearce said.
The incident likely wasn't serious, because if it was it would have been in the report, he said.
Quebec provincial police said they made Mohammadi's identity public on Saturday in the hope of locating a family member.
Martine Asselin, a spokeswoman for the force, said Sunday that a relative had yet to come forward.