Stephanie’s 21-year-old son, Malcolm, died in late 2015, after going into a coma following a 15-foot fall from a stairway railing. Malcolm’s 19-year-old girlfriend, Chloe, was the only person to witness Malcolm fall, and Stephanie says she is certain Chloe is responsible for her son’s death.

“The story I got is that Malcolm stepped back and fell sideways,” Stephanie says. “There is no way I can believe the story she gave me. Something she did that night caused him to fall. I believe she got mad. He was probably trying to dodge her, or she pushed him, and he fell over.”

Chloe insists she did not kill her boyfriend. She says Malcolm was intoxicated, lost his footing and fell backward.

“There were a good four or five steps between us. It wasn’t even like I was close enough to grab him,” she says.

According to Malcolm’s certificate of death, his manner of death was an accident.

In the video above, using a replica of the steps where Malcolm fell, Dr. Phil demonstrates how Malcolm may have fallen over the railing. After watching the reenactment, will Stephanie’s opinion change? This episode of Dr. Phil, “Deadly Accident or Push? A Grieving Mom vs. The Girlfriend Accused,” airs Wednesday. Watch more here.