Updated

Authorities arrested a prison guard and issued a warrant for another on charges they helped an inmate escape from a maximum security medical prison over the weekend.

A manhunt was underway for guard Vickie Sanford (search), 51, and inmate Edward McDaniel (search), 37, who is serving time for attempted murder.

The two allegedly walked out of the prison over the weekend during a shift change and drove away in Sanford's vehicle. Police believe Sanford gave McDaniel a corrections officer uniform before they left. Authorities did not know the nature of Sanford's relationship with the inmate.

Sanford's son-in-law, 28-year-old Michael Moize, who also is a guard at the prison, was arrested Monday night. He had not appeared in court by late Monday.

McDaniel escaped from Nashville's DeBerry Special Needs facility (search), which caters to prisoners who need medical care or mental health treatment. Officials would not disclose why McDaniel was there.

McDaniel serving a 20-year sentence for attempted murder; he was convicted of the 1996 shooting of deputy Joe Frazier when the officer stopped him on suspicion of drunken driving.

On Monday, Sanford's son, James Craig, pleaded for his mother to contact authorities.

"I can't believe it, but I've got to," he told WSMV-TV of Nashville. "I wish she would turn herself in, because this is destroying this family."

Craig said the situation caught Sanford's husband of 24 years by surprise. He also believes his brother-in-law is innocent.

"I know he didn't have anything to do with it," Craig said.

McDaniel was last seen at about 7:40 p.m. Saturday, when a corrections officer brought him medicine, officials said. Guards discovered him missing about 12 hours later during a routine check.

McDaniel's prison-issued clothes had been placed in his bed apparently to make it look like he was sleeping.

Sanford, who has worked at the prison off and on since 2002, didn't show up for work Sunday morning after completing her Saturday shift at about 9:30 p.m. She has no criminal record, according to the Department of Correction.

Sanford withdrew $2,000 from her bank account Saturday, said Tennessee Bureau of Investigation spokeswoman Jennifer Johnson.