Here are the details according to TMZ.
According to law enforcement … Keyshawn was involved in a fight with his ex-girlfriend when things allegedly got physical. Sources say he broke her phone, causing a gash to her hand.
Johnson was formally arrested for misdemeanor domestic battery and booked.
Keyshawn’s bail was set at $20k, he has paid that and has been released. Keyshawn besides his work with ESPN, had been in a feud with Justin Bieber over some incidents that happened when they stayed in the same neighborhood last summer.