The family of a 73-year-old dementia sufferer have filed a lawsuit against the police after obtaining a video showing police officers laugh and mock the aged woman after they forcibly arrested her for not paying $13 of items she got at a Walmart shop.

Karen Garner was detained on 26 June, 2020, after she walked out of a Walmart store in the state of Colorado without paying for $13 of items.

Her attorney has now released bodycam footage of the arrest and also a video showing police officers in the office mocking the grandma.

Her elbow was fractured and shoulder dislocated, says her attorney.

An investigation has been launched into the Loveland Police Department arrest.

In the footage, officers are seen from the booking area of the police station on the day of the arrest, fist-bumping one another as they review body camera video of the incident.

Video from inside Ms Garner's nearby holding cell shows the frail-looking grandmother slumped handcuffed to a bench while the officers joke about the incident, says her lawyer.

"Ready for the pop? Hear the pop?" one of the officers says at one point, referring to Ms Garner's shoulder.

As they continue to watch the footage, the same officer says: "I love it."

The grandma's family hired a sound engineer to enhance audio of the officers' remarks and have now filed a federal lawsuit against the department, alleging the officers violated the Americans with Disabilities Act and "violently assaulted" Ms Garner. They also alleged the incident has made her dementia ailment much worse.

Family Attorney, Sarah Schielke says her client went six hours without medical help while confused and crying in pain after an arrest that amounted to "torture".

"They failed Karen Garner," Ms Schielke said in a press release. "They failed the community. And they did it all on camera."

The bodycam footage of the arrest shows two police officers stopping Ms Garner as she was picking flowers by the roadside after she left the Walmart store in the town of Loveland, about 50 miles (80km) north of Denver.

CCTV from the supermarket shortly beforehand showed members of staff stopping Ms Garner to recover the $13.38 of merchandise, which included cans of soda and laundry detergent.

After she walks away from the officers, she is thrown to the ground, handcuffed, shoved face down on the bonnet of the police car and has her legs tied together with a hobble. She was left bleeding.

In a statement on Monday, April 26, Loveland police said they would not be making any comments pending the results of a "criminal investigation" launched last week.

The Larimer County district attorney is looking into the department's use of force during Ms Garner's arrest while Loveland police chief Robert Ticer has pledged full transparency with the inquiry.

One officer has been placed on administrative leave and two others moved to administrative duties.

See videos of the arrest and police mocking her below...