Holli and her sisters, Hillary and Heather, claim their parents, Shelly and John, are in a violent relationship that involves alcohol.

WATCH: ‘I Was Furious,’ Says Woman Who Claims Her Mother Drove Drunk With Grandkids In The Car

They claim their mother is a raging alcoholic with a violent streak and they’re worried for the safety of their father, who they say is putting his life at risk because their mother regularly abuses him. Shelly adamantly denies abusing John claiming she only strikes back when he gets violent with her.

TELL DR. PHIL YOUR STORY: Toxic Relative?

“I have a Master’s Degree in counselor education,” says Holli. “So, I understand the risk factors for domestic violence homicide. My father meets most criteria of risk factors for being killed by their partner.”

In the video above, Dr. Phil reviews the Lethality Screen, an evidence-based tool Holli says is used in her work at a domestic violence agency.

“Now, what we’re talking about here is - you’ve got drugs or alcohol, and the person refuses to acknowledge it and get help. Or, if there is physical abuse, those two are drop dead deal breakers, and you’ve got them both,” Dr. Phil tells John, affirming he’s at greater risk of serious injury due to Shelly’s behaviors.

Acknowledging that Shelly is in crisis, John may be in danger and their daughters are at the end of their rope, what solution does Dr. Phil propose? Will Shelly agree to go along with it?

Check here to find out where you can watch Friday’s episode.

Today’s Takeaway: Intervention? Have A Plan Before You Start