HOUGHTON — A Wisconsin mother and son are scheduled to face trial in October on charges of murdering a Hancock Township relative last year.

Margaret Kempainen, 50, and Jacob Kempainen, 21, were bound over to Houghton County Circuit Court Monday after a four-and-a-half-hour preliminary hearing in 97th District Court. The Hartfield, Wisconsin, residents allegedly conspired to kill Alvin Kempainen, 87, in December. Alvin was Jacob’s grandfather and Margaret’s father-in-law.

They were arrested the day after the incident in Clear Lake, Iowa.

Margaret’s daughter and Jacob’s sister, a minor who accompanied them on the trip, testified Monday Jacob told her he had shot Alvin twice after they arrived at his Hancock Township home, the second time at the direction of Margaret.

In police interviews after the arrest, Margaret and Jacob said they believed Jacob’s father had been involved with the occult, and Alvin had been possessed by spirits of previous victims when they arrived at the house. The claims resembled the plot of the M. Night Shamalyan movie “The Visit,” police said.

Margaret and Jacob are both charged with homicide – open murder and conspiracy to commit open murder. Jacob Kempainen, who his mother identified as the shooter, has an additional felony firearms charge. If found guilty, they could each be sentenced to life in prison.

Both Kempainens underwent forensic evaluations earlier this year, and were declared competent to stand trial.

The last date for a plea is Aug. 29. During Monday’s hearing, Prosecutor Dan Helmer said the Kempainens had rejected a plea offer.