The body of Gerald Washington, 57, was found Saturday night in the parking lot of a former high school. He had been shot once in the chest, investigators said.
Funeral arrangements had not been made as of Tuesday morning, City Clerk Andrea Mahfouz said.
Officials said Washington was found lying by his truck with his cap on and a pistol nearby.
Gary "Stitch" Guillory, chief deputy of the Calcasieu Parish Sheriff's Office, said his death is being treated as a homicide.
Washington, who served three terms as a city councilman, was sworn in Dec. 19 as Westlake's first new mayor in 24 years. He was set to take office Tuesday.
Although the town of 4,500 is 80 percent white, Washington had no trouble winning election in September. He had 696 votes _ nearly 69 percent of the vote _ to 318 for social worker Paula Johnson.
The city councilwill hold an emergency meeting Tuesday. The council has 10 days to appoint an interim mayor, and if it fails to do so by that deadline the governor could appoint someone to lead the town, according to Mayor Dudley Dixon, who is retiring after 32 years as mayor and council member.
"Mr.Washington is going to be missed by all the people of Westlake," Dixon said. "It's one of the most tragic things I've heard in a long time. He would be a good mayor."
"Westlake lost a good friend," said longtime Councilman Dan Cupit. "I was excited about the next four years. We all had good chemistry together."
Mahfouz said Washington was retired from the Conoco refinery, where he had worked for more than 30 years.
He and his wife; Mary Washington had an adult son and daughter, Mahfouz said.