Editor's note: Curtis Ray Watson has been captured Sunday. Read the latest update here. Our original story appears below.

A huge manhunt is underway in Tennessee for an inmate accused of killing a 64-year-old prison administrator before he escaped. The Tennessee Bureau of Investigation says 44-year-old Curtis Ray Watson is "extremely dangerous," and warns he may have left the state.

Watson has been on the run for three days. On Thursday, investigators said they secured warrants for Watson on charges of first-degree murder, aggravated burglary, and aggravated sexual battery.

The TBI has issued a statewide blue alert, which is used when suspects kill or seriously injure officers in the line of duty. Watson escaped from a prison about an hour north of Memphis, but officials warn he could be anywhere.

"This man is considered extremely dangerous and we need to find him," said Tennessee Gov. Bill Lee.

Newly-released surveillance images show Watson the day he escaped from West Tennessee State Penitentiary. Another photo shows what he would have been wearing: jeans and a blue Department of Correction shirt. Troopers have set up checkpoints for cars on roads leading to and from the prison, and are searching homes in area.

Watson had been in prison since 2012, serving a 15-year prison sentence for an aggravated kidnapping conviction. He was previously convicted of aggravated child abuse. Watson worked in the rural Tennessee prison as a farm laborer. Officials say he escaped on a tractor, and later abandoned it about a mile away.

Watson is suspected of murdering 64-year-old corrections administrator Debra Johnson in her home on prison grounds the morning he escaped. She had worked for the Department of Corrections for 38 years.

"Everything about Debra exemplified professionalism and her care for both the people she worked for, worked with, and the inmates that she served on a daily basis…" said Tony Parker, Commissioner of the Tennessee Department of Correction. "We will never be able to replace someone like Debra Johnson."

The Tennessee Bureau of Investigation released two of Watson's previous mug shots, in case he altered his facial hair, as well as images of Watson's tattoos, in hopes someone will be able to identify him.

The reward for information leading to Watson's capture is now more than $52,000. The TBI has received more than 75 tips that would place Watson across Tennessee and in some other states.