UPDATED 06/06/11 11:21 a.m.

CHICAGO (CBS) – Police are looking for a 67-year-old bar owner’s son, whom they believed stabbed her and killed her on the city’s Northwest Side overnight.

The stabbing also injured a witness.

As WBBM Newsradio 780’s Bernie Tafoya reports, police say the bar owner – identified by the Cook County Medical Examiner’s office as Henryka Waskowski, 67 — was stabbed in the neck shortly after 2 a.m. The stabbing occurred outside her bar, Henryka’s, at 5703 W. Irving Park Rd.

Police said Waskowksi was chased down the street and stabbed, along with a man employed at the bar.

LISTEN: Newsradio 780′s Bernie Tafoya reports

The 34-year-old employee told police a man believed to be Waskowki’s son began to chase them as they walked near the bar. He then took out a knife and stabbed his mother multiple times, including in the neck. The man was also stabbed in the back, police said.

Waskowski, of the 6400 block of West Berteau Avenue, was taken to Advocate Illinois Masonic Medical Center where she was pronounced dead at 3 a.m., the medical examiner’s office said.

The witness was also hospitalized for a minor stab wound to the back, but was later released, police said.

The “known” offender is at large, police said Monday morning, and is described as a 31-year-old man, 6-foot-1 and 300 pounds, bald with a light complexion, police News Affairs Officer Robert Perez said.

“They know who they’re looking for. It’s just a matter of time before they catch up to him,” Perez said.

The Sun-Times Media Wire contributed to this report.