Last week, a former Michigan player issued a series of threatening tweets directed toward Wolverines head coach Jim Harbaugh. The situation was threatening enough that the University of Michigan police department opened an investigation, and Harbaugh and Michigan AD Warde Manuel provided quotes on the seriousness of the situation.
Among the tweets in question:

On Sunday evening, the player in question -- Elysee Mbem-Bosse -- has tweeted an apology.
The Michigan athletics department or police department has not issued a comment on Mbem-Bosse's apology as of press time.