The assault on a woman was "background" to the case, Justice Geoffrey Venning said, and took place on the same date.
Justice Venning told the jury of seven men and five women that the male assaults female charge was "quite a different charge to the charge of murder", and that while Edmonds had admitted guilt to one charge, it did not imply guilt in the second.
"The plea of guilty to the assault charge is not related to the charge that you have to determine," he said.
"To a limited extent it is part of the background to the charge of murder."
That background and context would be provided when the Crown opens the case tomorrow, Justice Venning said.
The trial, which is expected to last two weeks, was adjourned for the day.
A number of witnesses are set to give evidence at the trial, including a psychic from Whakamaru, as well as a number of police officers from Auckland and Whanganui, a firefighter, pathologist, forensic scientists, and an ambulance officer.