I worked for years in the legal field, though usually civil law, not criminal. However, we had a client who years prior had been asked by a detective to come into the police station for an interview regarding a serious felony accusation against him. He did so, then was fingerprinted, mug shot, and released. Several weeks later he was told that no charges would be filed.
He thought that was the end of it, but later found out that his fingerprinting/mug shot was actually an arrest, and was reported to the state's crime bureau, and was on his background report. There was no mention that he wasn't charged, so the appearance is that he was charged and found guilty. This screwed up his life for many years, in so many ways, and our firm had to petition the court to change the criminal record to reflect that no charges were filed.
Long story, but the point is that even if charges are never filed against Steveson and Martinez, their arrest may be on their criminal record permanently - their attorneys should make sure that's not the case. Seems crazy and unjust that people apparently can be arrested, held, and that is on their permanent record, even if charges are never filed.