Mississippi state Rep. Jessica Upshaw at the Capitol in Jackson, Miss. on Feb. 20, 2008 AP Photo/Rogelio V. Solis

(CBS/AP) MENDENHALL, Miss. - Authorities are investigating the case of a Mississippi state legislator who was found dead Sunday, in what authorities say may have been a suicide.

Authorities said Rep. Jessica Upshaw, 53, was found dead at the home of former state Rep. Clint Rotenberry in Mendenhall, about 30 miles southeast of Jackson. Rotenberry was not arrested.

The Mississippi Bureau of Investigation was investigating Upshaw's death, said spokesman Warren Strain. He would say only that the death did not appear to be natural. Simpson County Coroner Terry Tutor also would not comment on the cause of death.

But Simpson County Sheriff Kenneth Lewis told WLOX-TV that Upshaw appeared to have shot herself in the head in an apparent suicide.

"It appeared she had a gunshot wound to her head; it appeared to be self-inflicted," he said.

Upshaw, a Republican from Diamondhead along the state's coast, died about 110 miles from her hometown.

"I have known Jessica for many years as an unselfish and dedicated public servant," Gov. Phil Bryant said. "This is a tragic loss for her family and all Mississippians, and our thoughts and prayers go out to her family during this difficult time."

Upshaw was the fifth Mississippi state legislator to die in as many months. The other four -- two representatives and two senators -- died of natural causes.

"Once again this session, the House has been touched by tragedy," House Speaker Philip Gunn said in a statement. "Rep. Jessica Upshaw was an outstanding legislator and friend. She was one of the brightest and most competent members of the House."

Upshaw graduated from the University of Mississippi and its law school. She represented Hancock and Harrison counties since 2004, according to her biography on the Legislature's website.

She chaired the House Conservation and Water Resources Committee and was a member of the Mississippi Legislative Conservative Coalition and American Legislative Exchange Council.

Outside the Legislature, she was affiliated with the Daughters of the American Revolution, the Colonial Dames and the Orange Grove/Lyman Chamber of Commerce.

Rep. Bobby Moak, the House minority leader, described her as a passionate champion of causes for her district and the state.

"This is an instance where replacement is not possible. Jessica will be sorely missed," he said.