At about 4:40pm Nov. 30th, a man in his late 20s was stabbed repeatedly in the head and face while using the restroom at the San Francisco Main Library.

According to police, the victim entered a restroom stall and noticed that there was a bag in front of the stall door as he entered. The suspect, a 40-year-old man, then kicked the stall door in and stabbed the victim in the head and face with a kitchen knife, allegedly believing that the victim had stolen his bag.

As the victim attempted to flee, the suspect continued stabbing him until an officer arrived on scene and took the suspect into custody. The victim sustained non-life-threatening injuries and was transported to the hospital. 

Update, 3:20pm:  The Examiner reports that the suspect has been identified as Louis Kessler, and that the pair knew each other and had been engaged in a confrontation outside of the library before the stabbing. The Ex notes that several bystanders, along with a "health and safety associate" named Christian Klotz, subdued the suspect and that he was locked in a security room until police arrived.