The bodies of 63-year-old Barry Bennett and his wife, Carol, were found Wednesday after a friend went to their home in Long Prairie for a welfare check.
Todd County Sheriff Todd Och said 22-year-old Dylan John Bennett is a suspect and asked anyone with information on his whereabouts to contact authorities.
Barry Bennett played 11 seasons with New Orleans, the New York Jets and Minnesota.
The Star Tribune reported Bennett had retired from teaching physical education in Long Prairie, a town of about 3,500 people about two hours northwest of Minneapolis. Superintendent Jon Kringen said Bennett rarely talked about his NFL career unless someone asked.