A knife-waving robber ripped off a northside cell phone store Saturday afternoon.
Police say the man walked into the Cricket store on West Ave. at Jackson-Keller just past noon.
They say he flashed a large hunting knife and demanded cash.
Police say store staff handed over the money and the robber then ran.
Officers set up a quadrant, and even called police from nearby Castle Hills, but could not find any sign of the man.
Police on scene did say the store has surveillance cameras, so investigators should get a good look at the robber.
Police did not say how much the robber got away with.