Madison police have identified a 20-year-old Fitchburg man as a suspect in the shootings that wounded at least three people early Saturday on University Avenue. Darrion D. Brown, who is being sought on a tentative charge of attempted homicide, should be considered armed and dangerous, said police spokesman Joel DeSpain. “Anyone seeing him should call 911,” DeSpain said. Brown could be driving a gold-colored 2001 Mercury Sable four-door car with Wisconsin license plate number 969-TLW, police said.