By Jennifer Armstrong
Updated November 18, 2010 at 09:06 PM EST

Three criminal charges have been filed against Amber Portwood, one of the four stars of MTV’s Teen Mom docu-series, after a seven-week investigation into alleged domestic violence, according to police in her hometown of Anderson, Indiana. The 20-year-old is accused of hitting Gary Shirley, 24 — the father of her 1-year-old daughter, Leah. Police launched the investigation after a September episode showed Portwood shoving him against a wall, slapping him, and choking him. Detectives uncovered two other videotaped incidents as well: On June 14, Portwood was filmed slapping, punching, and kicking Shirley; on July 18, she was shown slapping and punching him. Two of the charges are classified as felonies because of Leah’s presence; the third is a misdemeanor. Portwood could face up to three years in jail and fines up to $10,000 if convicted.