NEW ORLEANSA convenience-store clerk and customer were shot to death Monday in an armed robbery described by witnesses as "kind of brutal." "I don't know, you see lots worse stuff in the movies," said Ed Rozema, who was waiting in line to buy cigarettes at the time of the sort-of-chilling double homicide. "I mean, yes, it was unpleasant, but it wasn't the most gruesome murder in the world." Police at the scene agreed, saying they have seen far more horrific crimes. "The gunshots were clean and to the chest, so it's not like there was blood and brains all over the floor," said Sgt. Bill Culver of New Orleans' 33rd Precinct. "A murderer is going to have to work a lot harder to shock us."