Former police officer Beau Lamarre-Condon was charged with the murders of Jesse Baird and Luke Davies in February.
He is facing three new charges including domestic violence-related murder and aggravated break and enter with intent.
What's next?
Mr Lamarre-Condon's case is due to return to court on August 13.
New charges have been laid against former Constable Beau Lamarre-Condon, with police alleging the murders of Sydney couple Jesse Baird and Luke Davies were domestic violence-related.
NSW Police have charged Mr Lamarre-Condon with two counts of domestic violence-related murder and one count of aggravated break and enter with intent to commit an indictable offence.
These charges are in addition to the two existing murder charges he was facing.
The 29-year-old is accused of breaking into Mr Baird's Paddington home and shooting Mr Baird and Mr Davies with a police-issued handgun on February 19.
Mr Lamarre-Condon handed himself in to Bondi Police Station on February 23.
The bodies of the couple were found, more than a week after they were last seen, at a rural property in Bungonia, near Goulburn, inside surfboard bags.
Mr Lamarre-Condon has been in custody since he was charged.