The family of an inmate who died over the weekend while in custody at Harrison County jail plans to seek a second opinion on the cause of death.

An autopsy on Monday showed Lee Demond Smith, 21, died of a pulmonary embolus, a condition that involved a blocked artery in the lungs, said Harrison County Coroner Gary Hargrove.

The family’s attorney John Whitfield said that Smith’s age and developments in the criminal investigation involving the jail have raised some questions that Smith’s family wants answered.

Hargrove said the autopsy, which was performed by forensic pathologist Dr. Paul McGarry, makes the cause of death clear.

“It’s a condition like you hear happening to people who have been immobile for prolonged periods like on a bus or car or airplane,” Hargrove said. “Blood clots form in the veins around the legs and move up to the lungs and block the airway.”

Smith was in custody since Dec. 4 after being arrested on an aggravated assault charge following a shooting in Biloxi. His arrest violated his probation on a 2005 cocaine possession conviction.

Since 2002, four inmates at Harrison County jail have died of unnatural circumstances.

A June 2005 death was ruled an overdose involving prescription medication. Two other deaths, in 2002 and 2004, were ruled suicide by hanging.

On Feb. 4, Jessie Lee Williams Jr. was fatally beaten in the jail booking room.

Last week, officials said a fourth corrections officer pleaded guilty to federal charges of abusing inmates at the Harrison County Jail.