Mayor: Attack not related to Ferguson

• A 32-year-old man died after being assaulted Sunday by a group, at least 1 with a hammer


• Three juveniles have been arrested; police are still looking for a fourth suspect


• St. Louis mayor: "No evidence" that victim's race or ethnicity was related to attack


• Francis Slay: It isn't the fault of police that suspects' kin didn't know they were out so late

(CNN) -- The killing of a 32-year-old man on the streets of St. Louis with a hammer was savage, random and senseless -- but it was not, that city's mayor said, related to what's been happening in nearby Ferguson, Missouri.

The St. Louis metropolitan area remains on edge, a week after a grand jury decided not to indict then-Ferguson police Officer Darren Wilson in the shooting death of unarmed teen Michael Brown. That decision spurred emotional protests that sometimes devolved into looting and violence, unrest that carried racial overtones given that Wilson is white and Brown was African-American.

But any claim that 32-year-old Zemir Begic's brutal killing had anything to do with this Ferguson uproar "is absolutely unfounded," St. Louis Mayor Francis Slay said Monday on Facebook.

"There is no evidence that this was a crime occasioned by the race or ethnicity of the victim," Slay wrote in reference to Begic, who was white.

Police: Man beaten to death with hammers

The mayor made these comments after meeting with the family of Begic, who was beaten to death a hammer around 1:15 a.m. Sunday on a St. Louis street.

"I told them that our city mourned with them," Slay said. "... An innocent life was savagely taken."

According to a probable cause statement, Begic, his fiancée and two others heard yelling and then someone jumped on the back of his car. The 32-year-old got out, at which point a teenager -- identified by prosecutors as Robert Mitchell -- taunted Begic and "challenged him to a fight."

Then, "all four men began assaulting (Begic), and at least one of them struck (him) with a hammer," the probable cause statement added, noting the attackers continued to beat Begic after he fell to the ground.

He was unconscious by the time officers arrived, and pronounced dead after being taken to an area hospital.

As to his attackers, police said that, "after the assault, the juveniles fled the scene on foot."

Two of them -- juveniles age 15 and 16 -- were arrested later Sunday.

A third teen was in custody by Monday, at which point authorities said they were still looking for a fourth suspect.

Speaking about the attackers, Mayor Slay wrote on Facebook that "we do not know their past."

"Their futures, though, will be as grim as the judicial system can make it," he added.

Police will review patrol patterns in the Bevo area, where the attack occurred. Yet Slay scuttled any suggestion that they were somehow to blame.

"It is not the police department's fault that no family members had any idea that their young people were on the streets that late," Slay said. "Nor is it the police department's responsibility to educate or even to engage these young people.

"That responsibility, a community responsibility, is all of ours."

CNN's Mayra Cuevas and Dana Ford contributed to this report.