Roxanne Lewis-Randall claims her former boyfriend, Dr. Bert Franklin, was jealous of her son, Lincoln’s, biological father, Mel. Franklin, a dentist from Tulsa, Oklahoma is accused of causing the head injuries that killed the 19-month-old toddler in July 2016. Franklin, who says he’s innocent, is tentatively set to go to trial on first-degree murder charges in September.

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In a Dr. Phil exclusive airing Monday, Roxanne says Mel had been calling and texting her “all hours of the night, three or four nights a week.” She says this upset Franklin. Roxanne claims that just as she was telling him that Lincoln’s father wouldn’t be calling anymore, “at that same moment Mel texted me and so Bert got super angry and he said ‘I’m going to Game of Thrones your butt if you keep calling or texting.’” Roxanne claims Bert made other threats against Mel but says “I just didn’t take them seriously.”

On Monday’s Dr. Phil, Roxanne describes the events surrounding the night in July 2016 when authorities allege Bert Franklin fatally injured Lincoln. He’s accused of causing a blunt force trauma to the toddler’s head that left him with a fractured skull [not sure “cracked skull” is proper medical terminology – shouldn’t it be “fractured skull?”]. The Oklahoma dentist, who denies he harmed the boy, has been charged with first-degree murder. His trial is tentatively set for September 2017.

When does Roxanne say she grew suspicious of Bert’s alleged role in the child’s injuries, and what does she claim Bert did next?

This Dr. Phil exclusive airs Monday. Click here out where you can watch the full interview.

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Grieving Mom, Roxanne Lewis-Randall Describes Events From The Night Authorities Allege Bert Franklin Fatally Injured Her Toddler