A radio commercial for a local gun shop advises Houstonians to arm themselves against "Katricians," adding to the growing tension between Houstonians and the Katrina evacuees who have been blamed for a rising crime rate. Gun shop owner and radio talk-show host Jim Pruett said Thursday he started running the ad a few weeks ago after hearing a local television interview with a Katrina evacuee living in Houston who implied he would have to turn to crime if his government assistance ran out. "There are many evacuees here who are working," said Pruett, who has owned Jim Pruett's Guns &...