A witness to the Sunday night stabbing made a citizen's arrest Thursday morning, when he saw the suspect walking by Justin Herman Plaza.
"I've been a peacekeeper with Occupy SF since the beginning, it's kind of my job. I was a veteran in the military so I just feel it's another criminal off the street, thank goodness," said Nick Anthony Shaw with Occupy SF.
Friends say the man stabbed Sunday night remains in critical condition.
No one's been arrested in another stabbing that happened Monday night.