Authorities said Keith Lintz, 28, of Niles killed Carolyn and John Tarwacki on Feb. 5, 2010, at their Niles-area home. Authorities haven't discussed a motive.
Lintz is charged with first-degree murder.
At a preliminary examination Tuesday in Cassopolis, Patricia Wilds testified that Lintz came to her mobile home a few days after the killing and said he "didn't want to get caught." She said he had two guns with him and had fresh injuries.
Wilds was dating Lintz's cousin and didn't come forward to police until September 2012.
After hearing testimony, Judge Stacey Rentfrow ruled there's enough evidence for a trial.