PICKENS COUNTY, Ala. (WIAT) — Glenn Foster, a former football player for the New Orleans Saints, died while in the custody of the Pickens County Sheriff’s Office Monday afternoon. He was 31.

Foster had been arrested by PCSO Sunday on charges of assault and third-degree robbery and was taken to DCH Hospital Monday, where he later died. A cause of death has not been released. The Alabama Law Enforcement Agency has begun an investigation into Fosters’ death.

Foster, an Illinois native, played football at the University of Illinois before signing with the Saints in 2013 as an undrafted free agent. He would play in 12 games that season and record three sacks and eight tackles. Foster would play just five games in 2014 before being released from the team. He officially retired from the NFL in 2016.

Stay with CBS 42 as this is a developing story.