Baton Rouge police on Tuesday announced the arrest of a man in the Friday slaying of Sadie Roberts-Joseph, the 75-year-old founder of the city's African-American history museum who was suffocated and stuffed into the trunk of her abandoned car. Ronn Jermaine Bell Sr., 38, of Baton Rouge, is charged with first-degree murder in the death of Roberts-Joseph, whose autopsy showed she died of asphyxiation, including suffocation. East Baton Rouge Parish Coroner William “Beau” Clark released his preliminary findings on Monday. Baton Rouge police officials said on Tuesday that the alleged motive for the crime was $1,200 in back rent that Bell, a registered sex offender and tenant at one of Roberts-Joseph’s rental properties, owed the longtime community activist. Bell was initially booked into the East Baton Rouge Parish Jail Monday night on a fugitive charge after he apparently failed to pay a fee related to his sex offender status. He remained jailed Tuesday as officials announced the murder charge in Roberts-Joseph’s homicide. Baton Rouge police Chief Murphy Paul said the killing was not believed to be race-related, which had initially been a fear in the community. Both Roberts-Joseph and Bell are black. “There’s no information to lead us to believe this is a hate crime,” Paul said during a Tuesday afternoon news conference. 'I'm heartbroken that our community has lost such a kind and selfless soul in such a violent, tragic manner,' East Baton Rouge Sheriff Sid Gautreaux said. 'I have known and loved Ms. Sadie Roberts-Joseph for years and admire and respect her dedication to education and our community. 'Hate tried to silence Ms. Sadie, but her voice will continue to ring strong for peace and love through the countless people she touched.' Watch the entire news conference at the Baton Rouge Police Department below. The Advocate in Baton Rouge reported that Joseph’s body was found in the trunk of her car around 3:45 p.m. Friday in the 2300 block of North 20th Street, about 3 miles from her home. Prior to the news conference, Baton Rouge police officials had been tight-lipped on details of the case, and it was unclear what led to the discovery. Roberts-Joseph had last been seen alive around 11 a.m. Friday as the area was bracing for the arrival of Tropical Storm Barry. Smith ruled Roberts-Joseph’s death a homicide on Monday, three days after she was found. “It is with great sadness and respect we investigate any unexpected or traumatic death,” Smith wrote. “When our investigation involves an innocent victim, such as Ms. Sadie Joseph, it is particularly tragic. Our condolences are extended to Ms. Joseph’s family and friends.” Roberts-Joseph’s son, Jason Roberts, told WBRZ Monday the family was shocked that anyone would kill his mother. He gave the news station a message for her killer. “You stole light,” Roberts said. “You stole a warm, loving, giving and caring woman and it wasn’t just for her family. She cared for the city. She cared for you. “Her life should not have ended that way. She did not deserve that, but she would want forgiveness for you.” Listen to Jason Roberts talk more about his mom below, courtesy of WBRZ. Roberts-Joseph left her mark on the Baton Rouge community when she founded the Odell S. Williams Now and Then Museum of African-American History in 2001. The museum, now known as the Baton Rouge African-American History Museum, was named for a Baton Rouge educator. Roberts-Joseph had also been the organizer for the city’s Juneteenth celebration for several years. Baton Rouge police officials over the weekend wrote on Facebook that they mourned the loss of Roberts-Joseph with her family and the community. “Ms. Sadie was a tireless advocate of peace in the community,” the department’s post read. “We had opportunities to work with her on so many levels. From assisting with her bicycle give-away at the African American museum to working with the organization she started called CADAV (Community Against Drugs and Violence). Ms. Sadie is a treasure to our community, she will be missed by BRPD and her loss will be felt in the community she served.” Representatives of the Baton Rouge branch of the NAACP described Roberts-Joseph as a cultural legend. “From reviving Juneteenth to the culture preserved at her museum, she was a trendsetter and icon in this city,” the NAACP's Facebook post said. “#RIPower.” State Rep. C. Denise Marcelle wrote Saturday that her heart was empty over the loss of her friend. “This woman was amazing and loved her history,” Marcelle wrote. “She never bothered anyone, just wanted to expand her African-American museum downtown, where she continually hosted the Juneteenth Celebration yearly. I loved working with her and am saddened by her death.” WBRZ reported that Bell is on the sex offender registry because of a 2007 guilty plea to the sexual battery of a 9-year-old girl. Facing a life sentence for aggravated rape, he was allowed to plead guilty to a lesser charge, which saw him released after seven years in prison, the news station reported. A candlelight vigil was being held Tuesday night at the museum Roberts-Joseph helped found, the station said.