ANAMOSA, Iowa (AP) — Authorities say a man convicted of two murders in northwest Iowa has died of natural causes.

The Iowa Corrections Department said Tuesday that Paeng Saengaroun died Saturday afternoon. It's unclear whether he died in a prison or a medical facility. Prison officials didn't immediately return calls from The Associated Press.

The department says he was 67.

He'd been sentenced to life following his February 1997 convictions in Buena Vista County. He was convicted of two counts of first-degree murder for killing his wife and father-in-law in Storm Lake.