Step Up star Tricia McCauley found 'strangled' in her car after vanishing Christmas Day.

After going missing on Christmas Day, actor and yoga instructor Tricia McCauley has been discovered dead in her car in Washington DC.

The 46-year-old was last heard from at approximately 4.30pm on Christmas Day before she vanished, on her way to a holiday gathering.

An extensive search by police and friends followed, but almost 36 hours later, the Step Up actress’s body was discovered by police inside her white Toyota Scion with visible signs of trauma.

Police told The Washington Post she was found strangled and beaten.

The car had been parked on the street near a CVS pharmacy.

Following the discovery, Interim DC Police Chief Peter Newsham told the media on December 27, "We know that this is going to be excruciatingly painful for the family and friends, but after a media release relative to a missing person, we received a tip. Officers immediately responded to the 2200 block of M Street North West at approximately midnight last night. They found 46-year-old Tricia McCauley of North East Washington DC deceased in her vehicle."

Newsham said a suspect, named as 29-year-old Adrian Duane Johnson, was taken into custody shortly after the discovery, however, the timeline of what actually occurred still remains unclear. Johnson has been charged with murder.

After allegedly taking possession of the vehicle at some point on Christmas Day, it is believed that Johnson drove McCauley's car to at least six different locations across the Washington DC city area in the hours that followed into December 26.

It is alleged he drove the car with McCauley's body knowingly in the vehicle. The suspect is also believed to have robbed a CVS pharmacy and assaulted employees during this time.

The two were strangers, and it is not yet known when or how the suspect and McCauley first came into contact before she died.

D.C Police is now calling on the public for assistance, with Newsham saying, "We currently have a suspect in custody in the case, but we do need the public's help."

Mayor Muriel Bowser also addressed the media, saying, "Let me express on behalf of all of us in Washington D.C. our deepest condolences to her family, and I also want to thank the public in your assistance in helping us locate her vehicle and the person we believe is responsible for her death."

Bowser also encouraged anyone with information on the suspect's whereabouts on December 25 and 26 to contact police.