During a brief court appearance Wednesday, 32-year-old Chris Coleman answered "Yes, sir" when asked whether he understood the charges.
Coleman's wife, Sheri, and sons, 11-year-old Garett and 9-year-old Gavin, were found dead May 5 in their home in Columbia, just south of St. Louis.
Coleman was arrested Tuesday and charged with three counts of first-degree murder. Prosecutors haven't discussed a possible motive.
Judge Stephen Rice told Coleman that prosecutors will decide whether to seek the death penalty.
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