At a press conference starting 1 p.m. PT Monday, the family will "provide an accurate description of Peter, explain how the family attempted in vain to prevent the RCMP from killing him, and outline their plans moving forward," according to a release from the family's lawyer, Cameron Ward.
CBC News will livestream the press conference.
The B.C. Coroners Service is investigating the death, which it says followed a police shooting at a remote cabin in the Slocan area. DeGroot died at the scene.
DeGroot, 45, allegedly fired on police near the small community of Slocan on Oct. 9, after they showed up to investigate a dispute between two people.
When police returned fire, DeGroot fled into the woods, prompting officers to lock down the village and evacuate schools and homes.