Harrison County Coroner Gary Hargrove said a blood clot caused the death of an inmate at the Harrison County jail.

Lee Demond Smith, 21, of Biloxi, was taken by ambulance to Garden Park Medical Center shortly after 1 p.m. on Sunday after what appeared to be a seizure. The time of death was logged an hour later.

Smith was in custody for a probation violation on a cocaine possession conviction.

Hargrove performed an autopsy Monday.

All inmate deaths are investigated by the Mississippi Bureau of Investigation, the District Attorney’s Office and the county coroner’s office.

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.

Hargrove on Monday said it did not appear Smith had been beaten.