Gang violence is continuing to take a toll on Santa Ana, where police are investigating the death of a 23-year-old man shot dead in his grey BMW. “Obviously we have a gang problem,” said Santa Ana Police spokesman Sgt. Anthony Bertagna. “In any shooting, especially when people are driving down the road and people are shooting, [there’s] a concern that innocent bystanders can get hit.” The latest killing happened Feb. 6, where police said Nick Torres was shot dead at Bear Street and MacArthur Boulevard about 9:12 p.m. A female passenger in his BMW was uninjured. According to a police report, a witness saw a green SUV traveling eastbound on MacArthur Boulevard accelerate next to the gray BMW, and heard three to five gunshot before watching the green SUV drive away. Another witness reported hearing five gunshots and seeing a green SUV speed southbound on Bear Street. “I don’t know what led to this shooting myself,” Bertagna said. “I believe …