Police have revealed that the mother found murdered and stuffed into a duffel bag at her New York City apartment were a pair of squatters who beat the woman to death.

Nadia Vitels, 52, was found dead in the East 31st Street apartment in Manhattan's Kips Bay on March 14 after her family called the building superintendent to do a wellness check.

The medical examiner ruled her death a homicide on Friday after an autopsy ruled she died from multiple facial fractures, a brain bleed, two broken ribs and blunt-force trauma to the head.

Now, NYPD Chief of Detectives says the suspects - already believed to be a black male and a black female both in their 20s - were squatting in Vitels' apartment. 

'We believe that some squatters took the apartment over and this woman came home … and walked in on the squatters that were there,' Kenny said.

The two suspects were spotted driving off in Vitels Lexus SUV around the time they believe she died and even caught on surveillance footage which has not yet been released to the public.

Kenny added that the unique design of the 'upscale apartment' meant they may have been able to hide from Vitels for some time.

'The apartment itself is very unique in that there's no front door to apartment. You take an elevator up and then you key your way in. The elevator is actually your front door,' Kenny told the New York Post.

Michael Medvedev, Vitels' son, made the grisly discovery of his mother's corpse upon return alongside the building's superintendent Jean Pompee, who has lived in there for 22 years, after Vitels had not been seen for 48 hours.