Police have issued arrest warrants for two men in the slaying of a Fitchburg man. Dinkue Brown, 27, of Fitchburg and Dax Gibson, 36, of Gardner are connected with the killing of Luis Rodriguez, 26, says Worcester District Attorney Joseph D. Early Jr. The two are wanted on charges of murder, home invasion, and armed assault. Rodriguez was found bleeding on a neighbor’s porch around 2 p.m. June 21, Early said in a statement. Rodriguez was taken to Leominster Hospital, where he was pronounced dead a short time later, Early said.