Alyssa and Steven had two more children and knew nothing more of Katie until she contacted them via social media in 2016.
Katie, then 18, reunited with the Pladls, and moved into the family home to get to know her biological family. By then, Steven and Alyssa’s marriage was already in trouble so he began sleeping on Katie’s bedroom floor.
It wasn’t until Alyssa had moved out and later found an entry in their 11-year-old daughter’s diary that alarm bells began ringing.
Next to a drawing of a now pregnant Katie, she’d written, My dad calls her baby also his baby. My dad even says she’s my stepmum. He doesn’t even want me to say or call her sister any more.
‘I started to become hysterical, and I called him,’ Alyssa told CBS news. ‘I said, “Is Katie pregnant with your baby?” He just said, “I thought you knew. We’re in love”.’
Alyssa called the police, but that didn’t stop Steven and Katie getting illegally married.
Their son Bennett was born on September 1, 2017, and after wards, Steven and Katie were charged with incest and ordered to stay away from each other.
Bennett was put in the custody of Steven’s mother.
When Katie informed Steven their relationship was over and returned home to live with her adoptive parents, he was furious.
He killed seven-month-old Bennett before shooting Katie and her adoptive dad Tony dead in their car.
Steven then called his mother and confessed, before taking his own life.
Alyssa is furious that he was allowed access to Bennett and Katie after being charged.
‘They did not consider how sick a mind he had,’ she says.
For more, see this week’s that’s life! – out now!