Activist Sadie Roberts-Joseph, 75, founder of the Baton Rouge African American museum, was found dead in a car trunk on Friday. Police say the cause of death is unknown.

In a Facebook post, the Baton Rouge Police Department said,  “Ms. Sadie was a tireless advocate of peace in the community.” “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),” the Facebook post continued.

The BRPD is appealing to the public for help. You may call detectives at 225-389-4869 or Crime Stoppers at 225-344-STOP (7867).

[Photo Credit: Baton Rouge Police Department]