Former NFL running back Zac Stacy took a new mug shot on Monday ... before he was officially put behind bars for six months for attacking his ex-girlfriend in 2021.
Stacy posed for the photo at the Orange County Jail in Florida after he was remanded into custody following a judge's ruling at a sentencing hearing on Monday.
In the new picture, obtained by TMZ Sports, Stacy, wearing a striped shirt with a black collar, looked stoic -- and perhaps even a bit emotional.
11/13/21
HORRIFYING ABUSE
Stacy was ordered to serve the jail time -- as well as one year of probation -- after he cut deals with prosecutors earlier this month following allegations he was violent with Kristin Evans, the mother of his child, on multiple occasions in '21.