Law enforcement tells TMZ the mug shot stems from a DUI arrest in January.
We're told McNabb hashed out a plea deal with prosecutors and was sentenced to 1 day in an Arizona jail.
One law enforcement source tell us McNabb has already served his time ... though it's unclear when that happened.
It’s unclear why a mugshot has been taken of former Eagles quarterback Donovan McNabb. But a mugshot of McNabb has indeed been taken.
The mugshot also has been released publicly by the Maricopa (Arizona) County Sheriff’s Office, with no explanation of an arrest...
MCSO has released a mugshot of former Eagles QB Donovan McNabb. More details to come. pic.twitter.com/QpnNVMV2IR— AZ Family (@azfamily) April 17, 2014