Embattled former University of Iowa wide receiver Derrell Johnson-Koulianos (a/k/a "DJK") went on a recent Twitter rant leveling defamatory allegations against his old coach and current Iowa head football coach, Kirk Ferentz. DJK got in plenty of trouble at Iowa, and was kicked off the team in 2010 after a drug arrest. He never played again for the school, did not play in the NFL, and was unsuccessful in tryouts with the Arena Football and Canadian Football Leagues.
DJK alleges that Ferentz once required DJK to wear a trash can on his head during a practice, and was responsible for arranging the drug arrest that resulted in DJK's removal from the football team. DJK claims that all of this will be included in a book to be released in Iowa and Ohio in 2014, but no book deal has been arranged.
For a public figure to have a viable claim for defamation, the defendant must have said or written a false and defamatory statement of fact about a third person, with recklessness or malice, and no First Amendment privilege to do so. DJK's assertions are statements of fact that are likely false. If they are true, Ferentz has no claim, but DJK's veracity has been shown to be less than reliable in the past.
The statements were published via Twitter, and appear to have been published for the sole purpose of damaging Ferentz's reputation. If Ferentz can show he suffered damages because of the statements, which will not be easy, he has a viable defamation claim against DJK.