A third suspect has been indicted in the robbery and murder of a man found shot to death in a Mobile driveway last year, prosecutors said Thursday. A task force with the Mobile County District Attorney’s Office that deals with what the office deems as the county’s most dangerous defendants executed a search warrant Thursday afternoon on Ricki Thier, who was indicted earlier this month on a charge of felony murder in the March 2023 slaying of Michael Carmichael, the agency said.