Hours after police named him as a person of interest Mowatt went on the run and was found dead with self-inflicted gunshot wounds in Woodhill Forest, near Auckland.
Detective Inspector Dave Lynch confirmed yesterday that Mowatt would have been charged with two counts of murder had he not died, and that police had a strong case against him.
Mr Lynch said the investigation into the double murder and suicide had been completed recently.
"Police have previously stated that there was a 'strong inference' that John Mowatt was involved in the murders," he said.
"Police are now able to confirm that had Mr Mowatt been alive he would have faced charges of murder in respect of both Trevor Waite and Glenys Stanton. The police case has been independently reviewed by the Office of the Auckland Crown Solicitor who concur with the police view that Mr Mowatt would have faced murder charges and that the case against him was strong."
John Mowatt.
Mr Lynch could not comment on the specifics of the investigation, including how many times the couple were shot and how many firearms were used in the murders.
"The deaths of Mr Waite and Ms Stanton will now be referred to the Auckland Coroner."
A source close to the investigation said after Mowatt died police found a number of firearms at the property where he was living near Muriwai. It is understood they were found inside the house and in a storage unit.
Mowatt's family did not want to speak about the murders or the investigation.
Ms Stanton's brother-in-law, Andrew Michl, said it was a relief to reach the point where police would be able to present their evidence.
"Not a lot of good is going to come out of anything," he said.
"It's always hanging over us. But it'll be nice to get it behind us."
Mr Waite's mother Arlene said her family was pleased that police had announced that Mowatt was behind the murders.
Neither family wanted to speak further until the conclusion of the coronial process. Mr Waite, a father of three, was remembered by his family in a public notice published at the weekend.
His children Kelsey, Elliott and Claudia wrote: "Our dearest Daddy, we can't believe it's been a year, it still seems so unreal. It's hard to put into words how we feel, we miss you so much and hope you're okay wherever you are. You're always on our mind and forever in our hearts."
Read more:
*Bedroom murders: Tale of love and death
*Daughter's tribute: You were my world
His parents and siblings also wrote of their deep love and affection. "Taken from us cruelly and totally unnecessarily. No one knows how much we miss you. No one knows the bitter pain we have suffered since we lost you. Life has never been the same. In our hearts your memory lingers, ever strong, deep and true. There is not a day, dear Trevor, that we don't think of you."
Ms Stanton is survived by daughters Kristen and Nicole.
Case goes to Coroner
*Police have revealed the findings of the investigation into the deaths of Glenys Stanton and Trevor Waite.
*The couple were shot multiple times in the bedroom of Waite's Opaheke home on August 23 last year.
*The main suspect was Ms Stanton's ex-boyfriend, John Mowatt.
*It was confirmed officially yesterday that Mowatt would have been charged with two counts of murder had he not died.
