The body of a Louisiana mayor found shot to death is to be exhumed on Wednesday, as his family seeks to prove he was murdered, not a suicide.

Gerald Washington, the first black elected as mayor of predominantly white Westlake, was found dead Dec. 30, 2006, with a gunshot to the chest, his gun nearby. No suicide note was found.

Two autopsies, by state police and the local coroner, determined Washington killed himself. The district attorney has said he plans to close the case.

But Washington's widow, Mary, has said she believes her husband was murdered. She said the killing was covered up as part of a conspiracy.

Mary Washington and other family members hired an independent forensic pathologist to perform a third autopsy. Exhumation and a memorial service were set for Wednesday afternoon, said Lawrence Morrow, a family spokesman.

Washington, a longtime city councilman, beat a white candidate last year, winning 69 percent of the vote. Westlake is 80 percent white, a refinery town with a population of 4,500, about 140 miles east of Houston.

Washington, 57, had not yet taken office when his body was found in the parking lot of a former high school, his alma mater.

Morrow said the body will be taken to Houston, then flown to Pittsburgh for the autopsy by forensic pathologist Cyril Wecht.

Wecht has worked as a consultant on cases including Elvis Presley's death and the slayings of JonBenet Ramsey and Laci Peterson. Last year, he performed an autopsy on Anna Nicole Smith's 20-year-old son.