A Findlay man who’s serving time in state prison for murder is claiming he has killed again while behind bars.

37-year-old Joel M. Drain sent a letter to The Columbus Dispatch saying he assaulted 29-year-old Christopher Richardson at the Warren Correctional Institution in April.

Richardson later died at a hospital.

In his letter to The Dispatch Drain said, “I did it on camera, coaxed him in my cell. Beat him. Stabbed him. And strangled him.”

The Ohio State Highway Patrol has jurisdiction over prisons in Ohio and confirmed an investigation is ongoing and that Drain is connected to it.

Drain is serving 38 years to life in prison for the aggravated murder of 56-year-old Randy L. Grose, of Findlay, along with other felony charges.

Drain was also sentenced to another seven years in prison for the non-fatal stabbing of his father.