NFL's Justin Blackmon Arrested for DUI ... Again

Ex-NFL star Justin Blackmon was arrested for DUI in Oklahoma this weekend -- his 2nd DUI in three years.

The 25-year-old wide receiver -- a 1st round pick in the 2012 NFL Draft -- was arrested at 4:45 AM on Saturday morning in Carter County, OK.

He was taken to a nearby station where he was booked and posed for a mug shot.

The Jacksonville Jaguars player was suspended indefinitely from the NFL since last year ... when he was arrested in Oklahoma for marijuana possession.