Hernandez has been a suspect in the murder of Odin Lloyd, a semi-pro football player. Police have searched Hernandez's home twice, after Lloyd's body was found near Hernandez's home. As of right now, it is uncertain whether Hernandez has been arrested for murder, obstruction of justice, or something else.
Hernandez has been in trouble in the past, including failed drug tests at the NFL Combine. By releasing Hernandez, the Patriots illustrate that they will not put up with any misconduct. Much like the police, the Patriots have kept quiet about the investigation.
Unfortunately for Hernandez, it does not look like the day will be getting any better for him.
Here is some footage of the arrest: