The mother of accused killer cop Beau Lamarre-Condon has fiercely supported her son since his arrest and privately expressed doubts about him getting a fair trial.

Coleen Lamarre, who had her own long career with the NSW Police Force, believes her son was treated poorly at work and is deeply suspicious of her former employer.

The 63-year-old has regularly been seen when the alleged double murderer appeared in court but has otherwise shunned attention and been extremely reluctant to talk with reporters.

She has long been convinced her communications were being monitored by police and has told family and friends she might be under physical surveillance at some times. 

It is understood the mother-of-two had been using her background knowledge of law enforcement to assist Lamarre-Condon to prepare his defence, but police allege she went too far.   

Lamarre, who was charged on Wednesday with perverting the course of justice by attempting to influence a murder trial witness, now finds herself behind bars like her son.

She was arrested at her home in Balmain in Sydney's inner-west about 11.15am on Wednesday and refused bail to appear in court on Thursday morning.

'Homicide Squad detectives have charged a woman with allegedly attempting to influence a key witness to change their evidence in a high-profile double murder trial,' police said in a statement.

Lamarre, whose daughter also once worked for the cops, was taken to Day Street police station and charged with doing an act with the intention of perverting the course of justice.  

Beau Lamarre-Condon allegedly shot dead Jesse Baird, 26, and Luke Davies, 29, at Paddington in Sydney's eastern suburbs in February 2024.

The one-time celebrity chaser had reportedly briefly dated Mr Baird before the Network Ten identity began a relationship with Mr Davies.   

The 30-year-old former policeman has pleaded not guilty to each murder charge and is set to face trial in September. 

The Daily Mail previously revealed Lamarre-Condon had asked the NSW Law Enforcement Conduct Commission (LECC) to send an investigator to monitor his trial.

Lamarre-Condon has publicly accused some police who investigated Mr Davies and Mr Baird's deaths of 'serious misconduct and corruption'.

Daily Mail understands Lamarre-Condon has indicated he intends to call 50 to 60 witnesses in his defence - most of them police officers.

Lamarre-Condon has had three legal teams since his arrest and is now being represented by lawyers including barrister John Stratton SC and solicitor Ben Archbold.

When Lamarre-Condon was arraigned in the Supreme Court on October 3, he took the opportunity to deliver an extraordinary speech via audio-visual link from jail.

Lamarre-Condon said he would 'strongly oppose' any move to have the court closed or evidence suppressed when he faced trial because 'I want the public to know the actual truth of what happened'.

He then accused police who investigated Mr Davies and Mr Baird's deaths of 'serious misconduct and corruption', in which the DPP had been 'partly' complicit.

'The truth will always prevail and I will not be silenced,' he said.

Justice Hamill told Lamarre-Condon he was represented by a 'very capable solicitor' and noted there would be a record of any negotiations which took place in the local court.

Lamarre-Condon was originally charged with two counts of murder, later amended to indicate they were alleged to be related to domestic violence.

He has also pleaded not guilty to aggravated break and enter with intent to commit a serious indictable offence.

That charge is connected to an allegation Lamarre-Condon broke into Mr Baird's Paddington house and stole his wallet and phone in August 2023, six months before he and Mr Davies were killed.

The court heard there were more than 200 witnesses in the brief of evidence but the Crown did not expect to call 'anywhere near' that number to give testimony.

Mr Stratton told the court he did not anticipate applying for the case to be heard by a judge alone, meaning it would go before a jury. 

Lamarre-Condon, who joined the NSW Police Force in 2017, was a senior constable when he allegedly shot Mr Davies and Mr Baird with his Glock service pistol on February 19, 2024.

He then allegedly bundled their bodies into surfboard bags and dumped them at Bungonia, about 180km south-west of Sydney, where they were located on February 27.

A day before the bodies were found, Deputy Commissioner Dave Hudson revealed an alleged timeline of events leading up to and following the men's deaths.

Mr Hudson said gunshots were heard coming from Mr Baird's rented terrace house on the morning of February 19.

Later that evening, Lamarre-Condon allegedly hired a Toyota HiAce van from Sydney Airport and on February 21, drove the vehicle to a property near the tiny town of Bungonia with a female companion.

Lamarre-Condon allegedly left the property about 4.30am and drove to Newcastle, where he asked a former policewoman if he could borrow a hose to clean the van.

Neither woman is accused of any wrongdoing, and the female ex-cop spoke to police when her suspicions were raised.

About 10.30am the next day, February 23, Lamarre-Condon walked into Bondi police station and was arrested.

The bodies of Mr Davies and Mr Baird were found several hours after detectives spoke with Lamarre-Condon in the Metropolitan Remand and Reception Centre at Silverwater.

Before becoming a police officer, Lamarre-Condon ran a celebrity blog, posing in photos with visiting celebrities including Taylor Swift, Selena Gomez, Miley Cyrus, Harry Styles and Katy Perry.

Lamarre-Condon has spent the past two years behind bars over the shootings, which were allegedly the result of a months-long campaign of 'predatory behaviour' targeting Mr Baird.

He was sacked from the NSW Police Force in March 2024.