The circumstances around Trimmer’s death are still being investigated by the coroner.
Everyone involved in tragedy ‘really hurting’
Police Commissioner Col Blanch described the 29-year-old - who had migrated from the UK to join the police force in Australia - as “extremely well-liked” and with his “whole life ahead of him”.
“Our thoughts and deepest condolences are extended to his family and colleagues,” a police spokeswoman said on Monday.
Blanch told morning radio: “I know when my phone rings early in the morning from a senior officer, generally it’s not good news, and tragically it wasn’t.
“I know everyone that was involved is really, really hurting at the moment, and I think they wish they could just wake up from this nightmare.”
“It’s more important now for us to wrap around each other, to lean on each other. Can I thank the community and those involved – first responders and the broader parts of the community – for really offering their support to the family and fellow officers.”
As well as being on the beat, Trimmer spent time in the gang crime squad and tactical response group.
“He was a very, very competent, capable young man with his whole life ahead of him – that’s how sad this is,” Blanch said.
“This officer is an extraordinary officer who loved helping the community. He was a fine example of WA policing, and it’s just such a tragedy.”