Triple homicide killer Peter Dupas, serving three life sentences for the murder of three women, is likely to have an appeal request application dismissed after failing to meet the deadline.

Dupas put forward an application last year after he was served a third life sentence without parole, for the murder of 25-year-old Mersina Halvagis in 1997. However, the third sentence has no practical effect on his sentence as he was already serving two life sentences for the murders of Nicole Patterson and Margaret Maher.

The 58-year-old killer remains a suspect in the murders of three other women, and has served time in jail prior to his murder conviction. Dupas will still be able to file a new application seeking leave to appeal but would be required to meet higher criteria.