A 20-year-old in Park Slope was picked up by police and arrested for making a false report after placing four prank calls to 911 last week. What was the hilarious line that he was trying to get cops to believe? That one of their fellow officers had been shot in the head, even giving the badge number of the "wounded" officer. Police would go to each of the locations where the supposed shootings was, only to find nothing, and contact the officer, who was all right. Investigators ultimately recognized the voice of Daquan Gardner, who was arrested for a similar call in 2007. Just two weeks ago, Gardner had been arrested for smoking marijuana at Sixth Avenue and Fourth Street, the same area he was placing the calls from on a street pay phone. An investigator told the Post, "He got locked up, he was mad at the police and he was trying to cause trouble." One of the calls last week was placed just hours before Officer Omar Edwards was fatally shot in East Harlem.