Steven D. Sandison, 51, pleaded guilty to second-degree murder after admitting he killed his cellmate because he wouldn't stop trying to justify his child molestation conviction. (Screenshot: The Saginaw News/MLive video)

_________ Already serving a life sentence for murder, a 51-year-old Michigan inmate calmly told a judge earlier this week that he killed his cellmate because he was a child molester.

"If it's all right, I can tell you where it started," the inmate, Steven D. Sandison, told Chief Circuit Judge Fred L. Borchard during his second-degree murder plea in Saginaw County Circuit Court Tuesday. Sandison offered the explanation after his attorney, James Gust, asked if he had killed Theodore Dyer, his cellmate at Saginaw Correctional Facility, on Oct. 29, The Saginaw News/MLive reports.

"Oh, sure," Sandison replied. "Oh, sure, of course." Later, he explained, "The reason I killed him was because he was a child molester,"

Dyer, 67, who had lived in the Grand Haven area, was serving 25 to 50 years in prison for first-degree criminal sexual conduct. When confronted about his conviction, Dyer reportedly spent the evening trying to justify his actions.

Sandison said he hit Dyer in the face a few times. "When he fell, I wrapped a cord around his neck and I took his life," Sandison said.

Sandison will be sentenced on April 8. The second-degree murder plea could tack another life sentence onto the one he's currently serving in connection with a 1991 slaying in Wayne County. After Dyer's murder, Sandison was moved to Ionia Correctional Facility, where security is tighter. He told the judge expected to remain there indefinitely.