Chicago Police on Thursday afternoon were optimistic that video surveillance footage would help detectives identify the man who — apparently at random — grabbed a woman from behind and stabbed her repeatedly earlier this week in the Lincoln Park neighborhood.

“We may have discovered some helpful video,” police spokesman Anthony Guglielmi said Thursday afternoon. He refused to describe the contents of the video.

The stabbing occurred at 10:53 p.m. Tuesday in the 1200 block of West Webster.

Investigators have been scouring the area for any other surveillance video.

“So far, there is no information to suggest she knew the attacker,” Guglielmi said.

“It’s outrageous,” Ald. Michele Smith (43rd) said Thursday. “The offense is outrageous.”

The woman, 21, had been walking to the Fullerton stop of the CTA Red Line. She was about three blocks away when she was assaulted.

The attacker did not say a word to the woman, who was unaware she was being followed, police said.

He stabbed her multiple times in the upper body before running away, police said.

The woman was taken to Illinois Masonic Medical Center, where her condition was stabilized.

The woman was walking to the train after finishing her shift at a retail business in the area, Ald. Brian Hopkins (2nd) said Thursday.

The crime happened near the border of Hopkins’ and Smiths’ wards.

“Nearby witnesses saw the offender run off,” Hopkins said.

“Detectives are trying to compile a mosaic of video footage from before and after the attack,” he said.

“They have footage of varying degrees of quality and clarity and are not going to release anything to the public until they’re confident it could help identify this person,” Hopkins said.

The attacker was described as 5 feet, 9 inches tall; he was wearing a black hooded sweatshirt and black baggy pants, police said.

“Horrified,” Diana Acciari, 60, who lives steps away from the scene of the crime, said of her reaction to the stabbing.

“It seems like crime is getting worse and worse,” she said.

“I don’t understand what’s going on, why we can’t get a handle on this,” she added. “I’m trying to decide if I should put up a ‘neighborhood watch’ sign in my front yard but I don’t think that it would have mattered with something so heinous as this … maybe with petty crime.”

Chicago Police Near North District officers are increasing patrols in the area, Smith said.

Anyone with information should call police at (312) 747-8380.