The FBI is part of the ongoing investigation into the January death of a Walker County Jail inmate, authorities confirmed Thursday.

Anthony “Tony” Mitchell, 33, died Jan. 26 at Walker Baptist Medical Center, just over two weeks after he was arrested on charges that he fired on Walker County deputies as they responded to a welfare check requested by his family.

Lawyers for Mitchell’s mother have filed a lawsuit,claiming that jail deputies tased Mitchell and locked him in a freezer.

The federal lawsuit alleges abuse and medical neglect of Mitchell at the hands of Sheriff Nick Smith and staff at the county jail, including corrections officers, nurses and an investigator.

The lawsuit stated Mitchell froze to death. An emergency room doctor listed the cause of death as hypothermia and noted that Mitchell’s rectal temperature was 72 degrees.

The Alabama Attorney General’s Office released this statement Thursday: “We are aware of the allegations. The matter is being investigated by the Alabama Law Enforcement Agency (ALEA) and the Federal Bureau of Investigation (FBI). Once the investigation is completed, the Attorney General will ensure that any appropriate action is taken.”

Walker County Coroner Joey Vick on Thursday said he is still awaiting forensic results before he can determine the official cause of death. Those results could be a week or so away, he said.

The ordeal began Jan. 12 when Mitchell’s family members asked deputies to check on him, fearing he could harm himself or someone else.

Mitchell had a history of methamphetamine addiction. When deputies arrived at the scene, they said he pulled a handgun on fired on them and then fled into nearby woods.

SWAT officers, Alabama Department of Corrections tracking dogs and a helicopter were deployed to the scene.

He was found hiding in a metal out building. Officers used a flash bang – a distraction device – to make entry into the building.

He was taken into custody. Authorities said he had covered himself in black spray paint.

According to the lawsuit, Mitchell had lived with his father in Carbon Hill. He spiraled out of control in the months after his father’s death months ago, taking drugs and experiencing mental health problems.

He lost about 100 pounds in three months. He looked so “haggard and emaciated, that his cousin, Steve, said he almost didn’t recognize him when he showed up at his house.

“Obviously delusional, Tony told Steve that he, Tony, had a brother who had been stillborn, which was true. Tony further told Steve that his parents had put the baby brother’s body in a box that was hidden in the attic of the house.” This was not correct, according to the complaint.

Mitchell said he needed to rip out a wall in the attic to find his baby brother’s body, according to the family’s suit. He said there were two portals in the house, one to heaven and another to hell. He wanted to put his brother in the portal to heaven.

Steve took Tony to show him there was no box in the attic before calling 911 and reporting Tony’s mental breakdown and asking for an ambulance.

Deputies claimed in a Facebook statement that Mitchell fired a handgun at them before retreating into the woods where he was arrested

The suit says Mitchell was put in an isolation cell, not meant to hold inmates, in the booking area of the Walker County Jail where he was left for most of the 14 days before his death. He was not given medical care, according to the suit.

A still image from a security video shows a guard dragging Anthony Mitchell out of a shower room as he lies naked on the ground.

The room had cement floors with a drain but no bed or toilet, and Mitchell had nothing to sleep on. He also was left naked, according to the suit, possibly because of the jail’s “suicide watch” policy, until he was taken to the hospital, dying of hypothermia, 14 days later.

Corrections Officer Karen Kelly took video recordings of security footage of the events leading up to Mitchell’s death and shared them publicly. She has filed a lawsuit that alleges she was fired in retaliation afterward.

One video showed Mitchell being dragged, naked, across the floor by officers, according to the family’s suit. Another, from January 15, two days after he was taken to jail, shows him being tased, naked, by a group of officers in the doorway of his isolation cell, the family’s suit says.

Jail incident reports from the hours leading up to Mitchell’s death viewed by Kelly, according to the family suit, state two officers, Braxton Kee and Jacob Smith, found Mitchell unresponsive at feeding time, around 4 a.m. The family’s suit alleges he had been left for hours in a restraint chair in a jail freezer before the officers found him.

The suit says the jail kitchen typically opens at 3 a.m. and Mitchell was not taken to the hospital until 8:30 a.m.

“This means that after Tony was removed from the walk-in freezer or other frigid environment, at least five hours passed before he was transported to Walker County Medical Center, despite his obvious serious medical need for emergency medical treatment,” the lawsuit states, adding that his chances of survival dwindled by the hour as he suffered from hypothermia.

Security footage from 4 a.m. that morning showed Mitchell lying naked on a pile of trash on the cement floor of his cell as officers laughed at him, according to the suit. Video also showed jail nurse, Alicia Herron, enter the cell and spend a couple of minutes inside, appearing to give no medical treatment, according to the suit.

According to the suit, a video from 6 a.m., when a shift change happened, showed officers peering inside Mitchell’s room through the door. They brought a sleeping mat into his room. Nurse Brad Allred was recorded standing at the door of the cell looking at Mitchell. Officers began sweeping trash out of the cell as Mitchell lay on the floor.

At 8:30 a.m. officers removed Mitchell from his cell in a wheelchair. He was dressed in an orange jail uniform. He fell out of the wheelchair outside the cell and deputies put him back in it. His body made slow and spasmodic movements, according to the complaint. Deputies then picked up Mitchell and dragged him back into the cell, according to the complaint.

Four deputies then carried Mitchell outside the jail to an SUV. They placed him on the ground to open the door, allowing his head to rest on the concrete. In the video, he appeared unconscious. Officers then lifted him into the vehicle and drove him to Walker County Medical Center.

By the time they reached the hospital, the suit says, Mitchell was breathing with difficulty, only two to four breaths a minute. According to the suit, deputies did not tell hospital staff Mitchell had been put in a freezer. Mitchell was cold to the touch when he arrived in the E.R. according to the suit.

“Learning that Tony was hypothermic caused physicians to immediately change their course of treatment, as the measures they had initially employed were inappropriate to resuscitate a person who is severely hypothermic,” the suit stated. After three hours of trying to save Mitchell, he was pronounced dead at 1:15 p.m.

Following his death, the sheriff’s office released a statement that said Mitchell was alert and conscious when he left the jail and arrived at the hospital. “Shortly after arrival at the hospital, the inmate suffered a medical emergency and became unresponsive,’’ the statement read. “Life-saving efforts were performed by hospital staff and the inmate was ultimately revived.”

“Unfortunately, a short time later, the inmate passed away,’’ the statement read. “It is unknown at this time what contributed to his death.”

“Even though the inmate’s death did not occur in the jail, he was still in police custody so standard protocol was followed and ALEA was contacted,’’ according to the statement. “SBI agents began an immediate investigation into the incident.”

Following Mitchell’s death, a Facebook group called Justice for Tony Mitchell was launched. A protest is planned for Saturday afternoon at the Walker County courthouse.