Cell phone video shows the man San Francisco police say brutally assaulted former fire department Commissioner Don Carmignani, with some type of metal object.
"Right here, here, around the corner, in front of the gas station. He almost beat the man into the street with all these cars passing by," said one witness.
INTERACTIVE: Take a look at the ABC7 Neighborhood Safety Tracker
Several other people witnessed the attack which took place on Magnolia and Laguna streets in the Marina District, within a few paces from where Carmignani lives.
The man arrested is homeless and neighbors here say he befriended these two other homeless people who have made this area their home.
We spoke to one of them Nate Roye who gave us more details about the weapon that was said to be used by the alleged attacker.
"It wasn't a crow bar. It was two round pieces of metal that had been broken," said Roye who is from North Carolina but has lived on the streets of San Francisco for the past three years.
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Roye, who says he was with the attacker, claims they were sprayed with bear mace because Carmignani didn't like that they were hanging out near his home.
We asked him why hit someone over the head like that and attack him. "Because he was being disrespectful?" Roye said. We asked him who was being disrespectful. He responded, "The fat guy. There was a big old bald guy. Yeah, Don."
We asked him if that was reason enough to beat him up. "Yeah, sometimes," Roye responded.
"These types of brutal attack and these types of brazen attacks, these are the types of things that have been anxious about what's happening," explained Police Chief Bill Scott.
While other crime statistics remained steady or have gone down, the police chief is right.
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Bob Lee's case is high profile. What about other SF homicides?
According to the ABC7 News neighborhood Safety Tacker, so far this year the number of robberies has gone up by 14% compared to the same time last year and assaults are also on the rise by 2.2%.
Carmignani remains at San Francisco General Hospital with injuries to his head and face.
Civil rights attorney, Joe Alioto visited him and as we interviewed him, we were interrupted by someone incoherent.
"In San Francisco, we do not have a mechanism to take care of people who have mental health issues and so here we have a good example of this," said Alioto.