NEAR WEST SIDE — The sucker punch attack on a veteran Chicago alderman was captured on surveillance video from several angles.

Ald. Walter Burnett Jr. (27th) was talking with a resident outside the Near West Side's 27th Ward office about 7 p.m. Thursday when an unknown man punched him, knocking him to the ground.

In the new 90-second video, Burnett is seen walking up to the office's entrance next to a resident, with a coat over one arm and a bag in the other hand. A man appears in front of the two and punches Burnett in the face.

Stephanie Lulay on the bizarre attack on Ald. Burnett.

Moments later, several residents are seen running out of the office to check on the alderman.

"Someone burst inside [the office] and said 'Help! Help! Please help! The alderman is being attacked,'" a witness said. The man "clocked him," she said.

RELATED: ALD. BURNETT SAYS ATTACKER SAID HIS NAME WAS LUCIFER

At the time, a number of West Loop and Near West Side residents were at the office, 4 N. Western Ave., for Ward Night, a twice-weekly designated time where constituents can ask questions and air their concerns with the alderman.

Burnett refused medical attention and continued with Ward Night.

Chicago Police confirmed that an elected official was battered Thursday night with non-life-threatening injuries. A suspect is in custody, and charges are pending, said Officer Jose Estrada, a Chicago police spokesman.

On Friday, Burnett told DNAinfo Chicago that the man "said he was going to get me and get the mayor."

Before the 7 p.m. attack, the man who punched Burnett came to into the 27th Ward office earlier twice, at about 11 a.m. and 1 p.m., Burnett said. The 5-foot-9, 200-pound man became agitated after staff told him the alderman wasn’t in.

One office worker, fearing for his safety, grabbed a hammer and shooed the man out of the office.

“My staff said the guy was tripping. He walked across the street and stayed there all day,” Burnett said.

A man who punched Ald. Walter Burnett Thursday entered his ward office twice earlier in the day. [Provided]

Burnett said he believes the man who attacked him may suffer from mental illness.

“If he didn't have mental issues I don’t know why this happened. I don’t know if someone’s after me, if there’s a hit on me,” he said. "It's disturbing."

In his more than 20 years as alderman, Burnett has never been physically assaulted, he said. But on two occasions, he notified Chicago Police of serious threats that were made against him, but declined to pursue charges in those cases.

Earlier this month, Burnett's bike was stolen from the locked 27th Ward office, according to CBS2.

In his sixth term, Burnett represents parts of the West Loop, Greektown, Garfield Park, the Near North Side, Old Town, West Humboldt Park, West Town, the Medical District and Goose Island neighborhoods.

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