'Horrific attack': Mandurah man to serve 19 years in prison for killing ex-partner and mother of child

Junior Fayiah Carlos, 27, was sentenced in the Supreme Court on Thursday after he admitted to murdering his 19-year-old former partner Christine D'Cruz on December 31, 2017.

State prosecutor Craig Astill told the court Carlos had been served with a violence-restraining order against Ms D'Cruz earlier that month, but the pair were still in contact.

Mr Astill said the pair were looking for a new place for Carlos to live and had an argument about the prospect of him moving into a house they had visited on December 29, 2017.

Later the following night Carlos went to Ms D'Cruz's Mandurah home on Aldgate Street.

Mr Astill said the pair became involved in an argument in the kitchen after Carlos accused Ms D'Cruz of cheating and questioned if he was the father of their two-month-old child.

He said Carlos had consumed Jim Beam, a cask of goon, methylamphetamine, cannabis and sleeping tablets prior to the argument.

A doctor said Carlos was experiencing "substance-induced delusion".

Mr Astill claims Ms D'Cruz threw a Jack Daniel's bottle at Carlos and assaulted him with a dinner plate, before picking up a cooking knife.

Carlos retrieved the knife and proceeded to stab Ms D'Cruz 35 times to the neck, face, head, shoulders and back causing fatal injuries, he said.

Mr Astill said Carlos was a "violent man" who was first charged with assaulting a former girlfriend in July 2015.

He described the incident as a "horrific attack".

Judge Joseph McGrath told the court Carlos notified someone of the death 15 hours after, but said he had acted in self defence.

Mr McGrath said Carlos had an "entrenched history of substance abuse", consuming alcohol from eight-years-old and cannabis and methamphetamine since the age of 15.

Carlos was sentenced to serve 19 years in prison, before he would be made eligible for parole.

His sentence was backdated to December 31, 2017.