Aaron Hernandez's Brother Arrested After Missing Court Date, Smiling Mug Shot

D.J. Hernandez -- the older brother of Aaron Hernandez -- has been arrested after missing a court date in his ESPN brick-throwing case ... TMZ Sports has learned.

The 37-year-old former Division I football player turned himself into the Bristol Police Department at around 7 AM on Friday ... after authorities issued a warrant for his arrest following his no-show in court earlier this month.

According to police documents, D.J. was placed in handcuffs at the station ... before he was booked on a charge of failure to appear.

At one point during processing and fingerprinting, he took a mug shot ... where he was seen smiling ear-to-ear.

We broke the story, D.J. was originally hit with one misdemeanor charge of breach of peace in the case back in March ... after authorities alleged he threw a brick at ESPN's headquarters.

Officials accused D.J. of writing a note on the object that read, in part, "It's about time you all realeyes the affect media has on all family members."

"Since you're a world wide leader maybe you could lead how media and messages are delivered brick by brick. Clean it up!"