The Linn County Jail in Cedar Rapids is preparing to take in a high-profile prisoner, though 21-year-old accused mailbox bomber Luke Helder may not even go to trial. Sheriff Don Zeller says he’s preparing extra security for Helder, when and if he arrives.The F-B-I says Helder, the sole suspect in the mailbox bombings, has confessed to making and planting 18 devices in five states. Even if there is no trial, Helder would still need to appear before a federal judge, and Iowa was the first state from which federal charges were filed. Helder could be sentenced to life, if convicted. Sheriff Zeller says he’s planning for Helder to arrive by beefing up his forces. Zeller says this type of high-profile suspect creates problems and potential threats for his jail. He says this could be the type of crime where people are angry with Helder and want to get back at him.It’s unclear when, or if, Helder will be brought to Cedar Rapids.