Dramatic video shows the moment cops wrestle 'mercy killer' husband, 70, to the ground after he 'shot and killed his elderly wife because she had suffered a stroke and begged him to end her life'

A 70-year-old man has been accused of fatally shooting his wife of 40 years at a Mississippi rehab center in what police say may have been a mercy killing. 

Thomas Ballenger reportedly told investigators with the Clinton Police Department that he shot his wife Rebecca, 70, because she had suffered a stroke and said she didn't want to live that way.

Rebecca was found dead of multiple gunshot wounds at Woodlands Rehabilitation and Healthcare Center on Tuesday night. 

Dramatic video shows the moment Thomas was arrested by police after surrendering to the nursing staff outside of his wife's room following the shooting. 

He has been charged with murder and denied bond. 

Shocking video shows the moment Thomas was arrested by police after surrendering to the nursing staff outside of his wife's room following the shooting late Tuesday

After his arrest Thomas told police that he was depressed and had been feeling guilty about his wife's stroke. 

When asked if Thomas was on suicide watch, Clinton police Lt Josh Frazier told local news outlets: 'We're keeping a close eye on him.' 

The lieutenant also remarked: 'This is the saddest crime I've ever worked. 

'They were married. They were each other's shadows. They cared for each other a lot. But there is some indication the victim said she did not want to live like that.' 

Rebecca had been in the rehab center since she suffered a stroke in November, according to WJTV. 

Mercy killings are illegal in most states, including Mississippi.   

The suspect is reportedly a retired firefighter with a long history of service to the Hinds County community.  

In a statement Wednesday afternoon, the Jackson Fire Department said: 'To the family of Thomas and Rebecca Ballenger, this family has suffered a great loss. On behalf of Fire Chief, Willie G. Owens and the entire Jackson Fire Department, we are so very sorry for your loss. Our condolences and prayers are with the entire family at this time.'

Thomas has been charged with murder and denied bail. He is pictured above in his mugshot