Pasadena police arrested Brianna Kupfer's alleged killer Wednesday just a day after Los Angeles authorities released his identity.

Shawn Laval Smith, 31, is suspected of stabbing to death the 24-year-old UCLA graduate student during her shift at upscale furniture store Croft House in a random daylight attack.

Aerial images obtained by FOX 11 Los Angeles show police putting him into the back of a police SUV and later being transferred to LAPD custody.  

Smith, who police believe is homeless, has an extensive record spanning both coasts. He was released on a misdemeanor charge back in October, 2020.

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A law enforcement source told Fox News that Smith recently landed in jail in San Mateo after assaulting a police officer, and he had an active warrant in connection with the case after having his probation revoked on Nov. 30, 2021.

The tragic slaying has shaken Los Angeles where the homicide rate was up 11.8 percent in 2021 over the prior year – the highest it has been in more than a decade.

Smith allegedly walked into the North La Brea Avenue shop on Jan. 13 and stabbed Kupfer to death moments after she sent a message to a friend saying a man in the store was making her uncomfortable.

LOS ANGELES POLICE ID SHAWN LAVAL SMITH AS SUSPECTED KILLER OF BRIANNA KUPFER

"She sent a text to a friend letting her know that there was someone inside the location that was giving her a bad vibe," LAPD Lt. John Radtke said at a press conference Tuesday. "Regrettably, that person did not see the text immediately."

Smith fled out the store's backdoor. A customer walked into Croft House about 20 minutes later and found Kupfer lying on the floor in a pool of blood, according to police.

Brianna Kupfer (Kupler family  |  Crimestoppers war)

WHO IS BRIANNA KUPFER, THE LOS ANGELES STABBING VICTIM?

Authorities released surveillance footage showing Smith calmly walk into a 7-Eleven 30 minutes after the slaying and buy a vape pen.

"She was a kind soul and always was trying to make herself better and everything around her better," the victim's father, Todd Kupfer, told Fox News Digital Monday. "She cared about people."

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Originally from the Pacific Palisades, she was studying design in a graduate program at UCLA after attending the University of Miami.