'Narcissistic' engineer looked 'petrified' as he held knife and muttered 'I'm sorry' when sister of girlfriend who he raped and murdered found her sibling dead, court told

Arleta Derkacz said Stephen Sexton, 39, appeared 'petrified' and had 'dead eyes' when she arrived at the home he shared with her sister Joanna, 37, and found her dead.