There has been a major break in the investigation into the death of a beloved African-American activist in Baton Rouge. Her body was found in the trunk of her car. A short time ago, authorities now announcing they have a suspect in custody, and what they've now learned. Here's ABC's Alex Perez. Reporter: Tonight, police announcing an arrest in the murder of beloved Baton Rouge civil rights leader Sadie roberts-joseph. We received so many phone calls from the community when they learned it was miss Sadie. Reporter: Ron Jermaine bell, a convicted sex offender, has been charged with first degree murder. We believe that Ron bell was a tenant in one of her rent houses. We believe that he was behind several months on his rent. Reporter: The 75-year-old's body was found Friday, stuffed in the trunk of her car. In addition to creating the city's black history museum, roberts-joseph spent decades working to educate people. Tonight, a shattered community, and her daughter, vowing to protect her legacy. For those who were and are angry, live a better life. Give of yourself to your community to make the whole better. Reporter: David, the suspect has not yet entered a plea. Investigators do not believe she was the victim of a hate crime or targeted because of her activism. David? Alex Perez with us tonight, as well. Thank you, Alex.