A Phoenix liquor store clerk shot a would-be robber Saturday afternoon, after the robber pulled a knife on the clerk, police said.

Phoenix police gave this account:

About 12:30 p.m. two men went to a liquor store, near 23rd and Northern avenues after having been there two hours before.

During the second trip to the store, one of the men stayed outside. The other asked the clerk for a piece of paper.

As the clerk was waiting on other customers, the 29-year-old suspect wrote something on the paper. After the other customers left, the suspect handed a robbery note to the clerk. The clerk acted as though he couldn't read.

That's when the suspect came towards the clerk and opened a gate, which separates the clerk from the customers, and pulled out a knife. Seeing this, the clerk grabbed a gun and shot the suspect.

The suspect ran out of the store and across the street to a friend's apartment. He knocked on the door and collapsed. The friend called 911.

Police arrived and the suspect was taken to a local hospital where he remains in critical condition.