I looked up the Mazi Smith weapons charges. He got pulled over and was carrying a handgun in his car without a permit.
It's never good to see "felony charges" besides your name, but by football player standards, this is a nothing burger. The majority (of pros at least) own and/or pack guns, so Smith isn't doing anything out of line. He cooperated with the cops, and the Michigan AD defended him saying he's "not a threat to the university or community."
He'll be able to plead down to a misdemeanor because he's a D-1 football player and hopefully get the paperwork straightened out. Legally, he will probably be clear by the draft unless the prosecutor really wants to turn the screws. And I don't really see this as a sign of poor character moving forward.