Angela, a qualified teacher, worked as a teaching assistant at Rhyl High School so that she had more time to spend with her family.
She had moved back to north Wales from the Luton area after she split up from her husband, the father of her two sons. Her older son was away at university at the time of her death.
Angela had also wanted to be closer to her sister, Sarah Gunther.
Gunther told her nephew: “Tristan, I wanted to look into your eyes today and say this to you. The impact of your actions in taking Angela from us all, is something we now have to live with every single day.
“As a close family, we all fought so hard to try and get you the help you needed, none of us ever gave up on you – Angela especially. We all showed you love and cared for you, and tried to include you in everything we did.
“It is incredibly hard to express our feelings towards you now. There is anger, confusion, and heartbreak, but for me personally, there is still care there too for you.
“I just wish that if you felt you didn’t want to live under the same roof as Angela you had considered that it could have been resolved in so many other ways, without going to the extreme of taking her away from everyone who loved her.”
A statement by Angela Shellis’ older son, Ethan, was read out in court on his behalf. It said: “On that Friday morning when I tried to talk to mum, I knew then that something was wrong.
“At the time I could not comprehend the reality of what had actually happened, I knew something had happened but could never have imagined Tristan could of done this. I knew from the messages that it wasn’t my mum. I was begging for her to call me and I knew, had it truly been her, that she would answer me in an instant.”
He added that the stress had forced him to temporarily withdraw from university.
He said: “Not a day goes by where I don’t question why. Why would he do that to her? All my mum ever did was love Tristan, she looked after him and put up with way more than anyone ever should have, but that was my mum – she would do anything for us, anything for him, she’s the only person that’s ever done anything and everything for Tristan his whole life and he’s the one who’s took her from us all.”
Sentencing Roberts, Judge Rhys Rowlands KC said medical experts were “of the opinion that you were not suffering from any significant mental disorder such as would have had a substantial impact upon your behaviour at the time you killed your mother”.
“Rather you would have known what you were doing and been able to exercise self control. As such, whilst I don’t discount or ignore your mental health, it is a feature and does mitigate your behaviour,” he said.
