ST. PETERSBURG — Police launched an internal investigation after an officer looking into a call about a suspicious person shot and killed two dogs Sunday night. Officer Slobodan Juric was sent to the 4600 block of Sixth Avenue N after 8 p.m., a police statement said. There, he saw a group of neighbors and asked if they had encountered anyone suspicious. During the conversation, police said, two dogs on leashes began to attack another dog that was not on a leash. After the dog owners tried unsuccessfully to separate the dogs, Juric shot two dogs, a Rottweiler and a Chesapeake Bay retriever, and killed them. He fired his service pistol four times, police said.