RICHMOND, Ind. (AP) — An eastern Indiana man faces a preliminary charge of conspiracy to commit murder after admitting to poisoning his wife.

The Wayne County Sheriff’s Office says 69-year-old Alfred Ruf of Franklin Township in Wayne County is being held in the Wayne County Jail after being arrested Monday.

His initial hearing is scheduled for Wednesday. His wife, 51-year-old Lisa Bishop told authorities that she was being poisoned by Ruf.

Wayne County Sheriff Randy Retter says in a news release that Ruf told investigators he gave Bishop a substance knowing it would eventually kill her. Samples of the substance are being examined.