(CNN) Prosecutors have charged the suspect in the deaths of four people at a property management company in North Dakota with four counts of murder.

Chad Isaak, 44, was arrested Thursday, days after the killings at the RJR Maintenance & Management company, according to Mandan Police Chief Jason Ziegler.

He made his initial appearance in court Friday where a judge explained the charges to him and set his bail at $1 million.

Isaak was not asked to enter a plea. He replied, "Yes, sir," several times when he was asked at various points whether he understood what the judge had said.

CNN reached out to Robert Quick, Isaak's attorney, but didn't receive an immediate response.

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