A coworker was slapped with life in prison for beating and burning to death a store manager on Black Friday so that he could take her store keys and steal $50,000.

Clarence David Mallory, 22, was sentenced to spend the rest of his life behind bars in the death of Ashlea Ann Harris, 31, in a Fort Worth, Texas, courtroom on Thursday.

Mallory was found guilty along with his girlfriend Carter Carol Cervantez, 28, of killing the American Eagle store manager, who they both worked with, on Black Friday in 2014.

The couple bound Harris, brutally beat her and burned her body and apartment building in order to take the woman's store keys and steal $50,000.

Kevin Rousseau, Tarrant County prosecutor, said of their crime: 'At a minimum this took at least a month of planning. They stalked Ashlea Harris like people stalk a deer.'

Clarence David Mallory, 22, (left) was sentenced to life in prison Thursday in Fort Worth. He was found guilty of killing American Eagle store manager, Ashlea Ann Harris (right) on Black Friday in 2014. He killed Harris in order to take her keys and steal $50,000

Cervantez was recently found guilty of her involvement and sentenced to life in prison without parole in May 2016, reported the Star-Telegram.

She was blamed as the mastermind behind the murder plot by prosecutors.

Rousseau added: 'Imagine the horror, someone is probably sitting on you while someone else is taping up your hands and then your ankles.

'They slash her throat and then, when she is finally dead, they set her place on fire. There are a lot of people at her apartment complex, which says a lot about the defendants in this case.'

The couple had been fired from the American Eagle store at the Hulen Mall after being suspected of stealing nearly $18,000 from the store's safe in August 2014.

Then they turned their sights on Harris, who held the store keys, for their plot to make off with tens of thousands of dollars.

Mallory and his girlfriend, Carter Carol Cervantez, 28 (left), bound Harris (right), brutally beat her and burned her body. They set her apartment building on fire in order to cover up the crime

The couple had been fired from the American Eagle store at the Hulen Mall (file photo) after being suspected of stealing nearly $18,000 from the store's safe in August 2014

Harris was found dead in her apartment several hours later when firefighters responded to a fire alarm.

Her body was partially burned and she had been beaten. Harris’ hands and feet were bound with duct tape, police said.

A neighbor told police that he had heard a thump and screaming from the apartment, the police affidavit said.

The day after Harris' murder, Cervantez was caught by surveillance cameras trying to open the doors to the store, but they had already changed the locks.