A veteran police officer charged with murder had an extensive history of psychiatric problems, which has raised further concerns about Victoria Police’s handling of mental illness and its policies surrounding access to firearms.

The suicide of another police officer on Monday, who is also understood to have suffered from mental illness yet was armed with a service revolver, is expected to intensify pressure on Chief Commissioner Graham Ashton to act.

Force command has been accused of being slow to react to the increasingly erratic behaviour of several officers, who were deemed fit to work and permitted to carry firearms.

A Victoria Police spokeswoman said the force had strict policies to the ability of members to carry personal firearms which take into account, health, wellbeing and welfare issues.

“Members are monitored very closely in relation to carrying a firearm. We are not complacent and continually review these policies to ensure they remain robust, and we look for opportunities to improve,” the spokeswoman said.

Senior Constable Tim Baker, 44, is understood to have suffered serious mental health issues for almost a decade before he killed Vlado Micetic during a routine intercept in Windsor in 2013. He was charged with one count of murder last week, after shooting Mr Micetic three times in the chest and claiming he acted in self-defence.

Mr Baker took extended leave on several occasions because of his illness, and was only allowed to resume work after approval from a Victoria Police psychiatrist.

But less than a year before the shooting, it is believed Mr Baker was involved in a serious altercation with another officer during Operational Safety Tactics and Training that should have set off alarms, according to colleagues of the accused man.

During firearms training, an instructor placed a hand on Mr Baker to assist with his stance. According to a source, Mr Baker responded: “take your hands off me or I’ll f…ing kill you”.

Two former colleagues have expressed serious concern that Mr Baker was subsequently issued with a gun and permitted to work alone.

“He should not have been operational and he definitely should not have been working by himself. It’s a failure of the department and Tim’s supervisors, they’re the ones who should also be held accountable for this tragedy,” said a former colleague.

Another officer, who worked briefly with Mr Baker, said his mental health issues were widely known and he had received professional help.

Police Association secretary Ron Iddles refused to discuss Mr Baker’s case, but said more than 200 officers had gone on sick leave over the past year because of depression and post-traumatic stress.

As Victoria Police force grapples with the issue of mental health and an entrenched history of “suffering in silence”, Mr Iddles urged more members to seek help when they were unable to cope with the demands of the job.

The state coroner is presently investigating at least four police suicides, including the death of an information technology specialist at the Victoria Police Centre in June, who did not carry a weapon as part of his daily duties, but was issued with a gun by the transit safety division.

The man shot himself at a Rosanna primary school, where his estranged partner is believed to have worked.

A senior police officer said the man should never have been given the weapon .

“The force hasn’t always been great at dealing with (the) mental health or stability of its people. Obviously the job’s stressful and people handle it different ways, and there’s definitely some coppers who shouldn’t have guns.”

A Victoria Police spokeswoman said the force had appointed Deakin University to assist with a workplace analysis, while also undertaking an internal review of the welfare work and support it provides to officers.

“The Chief Commissioner has commissioned an external review to look at what more Victoria Police can do to best manage the issues surrounding mental health to ensure that going forward we deal with these issues in the best way possible,” the spokeswoman said.

This article first appeared on ‘The Age’ on 13 October 2015.