Tara Lambert says she once had a great friendship with Kellie Cooke, the woman she hired a hitman to kill. Lambert says she grew close with Cooke, her husband’s ex and mother of his children -- but that quickly ended when Lambert claims Cooke “turned” on her.

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“She was keeping the kids from us,” Lambert tells Dr. Phil in an exclusive interview airing Monday. “It was every month. It was, she was going back to court for something.”

So Lambert says she decided she needed to show Cooke that enough was enough and to leave her family alone. The former model says she enlisted the help of a high school acquaintance, Ginny, to make a threatening phone call to Cooke. After that, Lambert asked the acquaintance if she knew someone who could “take care” of the problem.

WATCH: ‘I Wanted Someone To Beat Her Up,’ Tara Lambert Says About Ex-Friend She Hired A Hitman To Kill

In the video above, Lambert claims that Ginny was pushing her to meet with a hitman – an accusation Ginny adamantly denies.

This episode airs Monday. And, on Monday, the victim, Kellie Cooke, and Ginny, sit down together for the first time in an exclusive interview to tell their stories. Plus, on Tuesday, see video of the undercover police sting in which Lambert was laughing as she requested Cooke be put through a wood chipper. Check here to see where you can watch.

‘You Had Numerous Opportunities To Reconsider This And Come To Your Senses,’ Dr. Phil Tells Former Model Convicted Of Hiring A Hitman