Watch: After Gay DC Lawyer Found in Car, Cause of Death Revealed

The cause of death has been revealed in the case involving an openly gay lawyer whose body was found inside a stranger's car in Washington, D.C. in March.

A spokesperson for the D.C. medical examiner confirmed to NBC Washington last week that Daniel Potucek, 34, died of an accidental overdose of MDMA.

Potucek, a lawyer for the Transportation Security Administration, was found in a stranger's car in D.C.'s Shaw neighborhood on March 31. At the time, police called the incident a death investigation but Potucke's mother said things didn't make sense, as his wallet, debit card, house keys and phone were missing.

"I've been told that somebody put him in that car," Lorinda Potucek, told NBC Washington, adding that she said she was told the car door had been unlocked.

The car belonged to Alexander MacLennan, who parked his Mazda SUV before going to a restaurant. After having some drinks with his partner, MacLennan decided to take a Lyft ride home instead of driving. He planned to pick up his vehicle the next morning while on a jog. When he went to get his car, he said the street was blocked off. After running some errands, he returned to the area but realized his SUV was gone.

"We just assumed it was stolen and having seen the police there earlier in the day, I just thought maybe, I don't know, something got smashed," he told NBC Washington.

After reporting his car stolen, he learned that his car was part of a death investigation. MacLennan said he did not know Potucek and did not know how he got into his car.

Watch NBC Washington's report below.