She was the trusted best friend called upon to perform the "boyfriend test", and from the moment she met Michael James Quinn at community markets she did not like him.

In the Supreme Court on Thursday, Medina Hasic described the man accused of fatally stabbing her childhood friend as insecure, controlling and overbearing.

Michael Quinn appears in Kiama Court in July 2013 charged with murder. Credit:Andy Zakeli

"I think that he was obsessed with her and he wasn't planning to live without her," Ms Hasic said.

Mr Quinn is accused of stabbing his on-off girlfriend Cherie Vize, 25, in the neck, before stabbing himself, on the front lawn of the Wollongong home where he lived with his parents in July 2013.