The sentence hearing of a man who stabbed his stepson to death is due to get underway later today.

David Mahon has been in custody since he was found guilty of Dean FitzpatrickÂ’s manslaughter earlier this month.

The 45-year-old, whoÂ’s married to Dean's mother Audrey, admitted holding the knife that caused his death on May 25th 2013 but claimed it was an accident.

His sentence hearing is due to take place at 2 oÂ’clock this afternoon.