San Francisco Police released video on Monday for help finding a man suspected of beating a 74-year-old North Beach portrait artist who later died from his injuries.

On Dec. 5, San Francisco resident Stuart Jackson was standing at a bus stop on the corner of Van Ness Avenue and Market Street about 2 p.m. when he was suddenly assaulted by a young, muscular man, said Officer Albie Esparza, a police spokesman.

During the unprovoked attack, Jackson fell and hit his head on the pavement. He was rushed to the hospital, but later died from his injuries, Esparza said.

An artist known to the community, Jackson liked to sketch in various bars and coffee shops in North Beach, his older brother Bob Jackson said.

Marc Dierkes, a friend of Jackson’s, said he was a one-of-a-kind resident in the area.

“He was kind of a unique, local character and a lot of people were familiar with him,” Dierkes, 60, said in December. “I’m still sorting through it.”

Police are looking for a 25- to 35-year-old man man described as 6 feet tall, with a muscular build. In a video released by police, the alleged attacker is walking down a street wearing a black hat, black pants, a black long-sleeve shirt and a dark vest jacket.

Anyone with information on the incident can call the anonymous tip line at (415) 575-4444 or text tips to TIP411, beginning the message with SFPD.

Jenna Lyons is a San Francisco Chronicle staff writer. E-mail: jlyons@sfchronicle.com Twitter: @JennaJourno

Market St & South Van Ness Ave

Market St & South Van Ness Ave