Officers charged the 57-year-old Wanneroo man with murder last Thursday.
In the early hours of August 29 last year, officers were called to a Mundi Place home after the accused reported Phaea Leanne Lightfoot (51) had shot herself.
Acting Major Crime Squad inspector Carlos Correia described forensic science’s role in raising suspicion around the incident.
‘There were elements of suspiciousness that we had to look at and that all came down to forensic science,’ he said.
‘There was a lot of work done in that area to reach a stage where we spoke with the accused again and made a decision to charge.’
Due to the gradual process of forensics, they had been unable to make a charge until a year later.
‘Things have to be done a certain way and sometimes it’s not locally, it could be nationally and internationally,’ he said.
‘A lot of the forensic work does take time; it’s not something that comes under our control.’
He said the deceased woman’s family were made aware of the murder investigation, but police had kept it quiet from the public.
‘We didn’t want the person of interest or anyone else knowing what we were doing,’ he said.
The man appeared in Joondalup Magistrates Court last Friday, where he was remanded in custody to appear in Stirling Gardens Magistrates Court on July 31.