(CBS) — Relatives of a dead southwest suburban teenager don’t believe they’re getting all the facts about her death, and they want police to say more.

WBBM Newsradio’s Bernie Tafoya reports 18-year old Brittany Wawrzyniak died in November in Worth. Police said she had jumped out of a moving car during an attempted drug buy.

Wawrzyniak’s said they don’t know if she jumped or was pushed, but claim she definitely was not planning to buy drugs from accused pusher Eric Steven Johnson.

Cook County prosecutors have said Wawrzyniak got into Johnson’s car on Nov. 8 to buy 30 pills of clonazepam, an anti-anxiety medication. After paying Johnson $200, Wawrzyniak wanted to count the pills, but Johnson started driving off.

Wawrzyniak wanted to get out of the car, and jumped out of the back seat, hitting her head on the pavement of a parking lot at 115th and Beloit, in Worth, prosecutors said.

Johnson, 21, of Midlothian, has been charged with unlawful delivery of a controlled substance. He was being held at the Cook County Jail on $300,000 bond.

Wawrzyniak’s cousin, Al Zuccarello, said she was trying to set up an ambush confrontation between Johnson’s girlfriend and another young woman with whom she had a beef.

“It was basically a ruse to get the girl that was selling the drugs to the park,” Zuccarello said.

Worth Police Chief Martin Knolmayer said detectives are waiting for lab results in the case, and until then the investigation remains open.

“It’s a very tragic, unfortunate event. The case is under investigation. There is a pending criminal trial. The investigation continues,” he said.