Pierce was suspended by Iowa, but no clue if the school followed its policies at the time or not. I note that Wikipedia cites an ESPN article which notes that Iowa's actions were "atypical, as the school usually waits for the legal process to play out before making a decision, but the school took swift action because of the severity of the charge." He pled guilty to a lesser charge and judgment was deferred. He sat out a year after the plea bargain. He then came back and played. He then got arrested after a domestic violence incident and was kicked off the team. He was convicted and served time.
The allegations against Pierce were particularly nasty in nature.
As for Miller, no charges were ever filed against him in connection with the murder. It appears he was truthful with the cops, whereas others were not, and his version of events matched video and witness statements.