RIPLEY, Tenn. -- A Tennessee inmate charged with killing a corrections administrator before he escaped a prison was seen riding a tractor outside a lawn mowing shop at the facility about a half-hour before a search for him began, prison officers testified Wednesday.

Curtis Ray Watson appeared before a judge during a hearing in a Lauderdale County court. A judge is expected to rule whether there is enough evidence to present the case to a grand jury, which will consider whether to formally indict Watson on murder and escape charges.

Watson was on regular lawn care duties at West Tennessee State Penitentiary near Henning on Aug. 7, authorities said. Investigators say Watson sexually assaulted and killed corrections administrator Debra Johnson at her home on prison grounds that morning.

Watson escaped on the tractor, which was found in a cotton field about 2 miles (3 kilometres) from the prison, authorities said. Watson was found four days later after an intense manhunt.

Watson, a two-time felon, has not entered a plea in the case. Prosecutors are considering seeking the death penalty, Lauderdale County district attorney Mark Davidson has said.

Watson has been serving a 15-year sentence for especially aggravated kidnapping. He also had been previously convicted of aggravated child abuse. Watson had access to a tractor and a golf cart as a "trusty" -- an inmate granted special privileges as a trustworthy person, authorities said.

Prison officers testified that they briefly could not locate Watson during the morning of his escape. They located Watson's golf cart at Johnson's house at about 8:30 a.m., but Watson was not found until about a half-hour later as he was riding the cart, prison officer David Shelton said.

Phone records show Johnson was talking on the phone at 8:10 a.m., about 20 minutes before corrections workers saw the golf cart at her house, according to an affidavit. When Johnson didn't show up for work, co-workers discovered her body at her home at 11:30 a.m., according to the affidavit, which notes that agents found a cord wrapped around her neck. A medical examiner declared her death a homicide by strangulation.

Watson was again seen on a blue tractor outside the lawn mowing shop where he worked at 10 a.m., prison officer Kenneth Edwards said. At that point, Watson told officers he was going to a maintenance shop, according to testimony.

Officers said Watson did not show up for a head count at 10:30 a.m., and a search for him began. Shelton testified he notified his supervisor that Watson had escaped at about 20 minutes later. A box cutter was found to be missing from Watson's collection of tools at the lawn mowing shop.

Defence attorney David Stockton questioned officers about their supervision of inmates at the prison. Officers said they keep watch over about 80 inmates on work duty. Shelton testified that Watson displayed good behaviour as an inmate and that it did not strike him as unusual that Watson would be at Johnson's house.

Johnson had been a state employee for 38 years and oversaw wardens at several area prisons.

Six more witnesses were expected to testify Wednesday afternoon.