A teenage boy under arrest for robbing a Marshalltown Credit Union will not be tried in federal court, as most bank thieves are. Marshalltown Police Chief Lon Walker explains.Walker says federal officials have declined to prosecute because the feds don’t file bank robbery charges against juveniles. State charges have been filed. Fifteen-year-old Fernando Samuel Garcia faces state charges of first degree theft and second degree robbery. Garcia’s also been charged with interference with official acts for running from the cops. The robbery happened just before noon on Monday. A Marshalltown resident listening to the radio heard a description of the suspect, and tipped police off when they spotting someone they believed to be the suspect getting into a vehicle a few blocks from the bank. Walker says cops recovered all of the stolen money as well as the gun, the ski mask and the clothes witnesses say Garcia was wearing.