“If you like your knife, you can keep your knife. Period. Nobody will take it away from you.”
I recall a few years back, that an American Indian was whittling a piece of wood as he walked a city street in the Northwest (Oregon or Washington), and a cop stopped, got out of his police car and gunned him down and killed him. Just for whittling a piece of artwork.
So they might not take your knife, just your life.
Found a link. Audio in the video has multiple shots fired under a second after ordering him to drop the knife, the Indian was half-deaf and didn’t hear the cop.
http://www.copblock.org/1451/police-officer-murders-half-deaf-hobbling-native-american-man/