Joe Mixon's sister turned herself in to authorities on Thursday after she was charged for her alleged role in a shooting at the NFL star's home earlier this month ... and on Friday, she pleaded not guilty to all counts -- TMZ Sports has confirmed.
Shalonda Mixon, the 34-year-old sibling of the Cincinnati Bengals running back, was booked into Hamilton County Jail at 6:54 PM Thursday ... and spent the night behind bars, records show.
A Hamilton County court official tells us she had an arraignment hearing on Friday morning, where she pleaded not guilty to one count of tampering with evidence and one count of obstruction of justice.
Her bond, the court official said, was then set at $5,000.
Prosecutors have accused Shalonda Mixon of attempting to cover up a shooting that happened at Joe Mixon's house in the Cincinnati area on March 6.
According to prosecutors, Shalonda Mixon's boyfriend, Lamonte Brewer, shot at a teenager who was playing with a toy Nerf gun near the football player's backyard -- striking him once in the foot.
Shalonda Mixon then allegedly tried to scoop up the shell casings, before fleeing the scene with Brewer in a car. Prosecutors say she's facing up to four years behind bars if convicted.
Brewer has also been charged in connection with the shooting -- he was indicted for, among other charges, felony assault on Thursday -- and is facing up to 20 years behind bars if convicted.
Joe Mixon, according to prosecutors, did not commit a crime and is not facing charges. His agent, Peter Schaffer, released a statement Thursday saying the NFL star and his family had been fearful recently after receiving death threats the last few weeks.