LEESVILLE — After deliberating for less than an hour, a state district court jury on Thursday convicted Matthew Dotson of two counts of first-degree murder in the deaths of girlfriend Misty Marshall and her 9-year-old son, Day-Min.

“This was a man who was cold and callous and uncooperative with authorities during our initial contact with him and throughout the investigation,” said Sheriff Sam Craft. “I am glad that justice was served so that this family can begin to get some closure.”

Dotson will be sentenced Oct. 13. The state is seeking life sentences for the convictions.

Marshall and her three children were reported missing on Dec. 4, 2015, by her family, who said they hadn’t heard from her since Thanksgiving. The bodies of her and her son were found on Dec. 17, and Dotson was arrested a short time later.

Prosecutors said Dotson killed Marshall after she discovered him molesting her son. They said he disposed of the boy’s body in an abandoned vehicle.

He then forced Marshall’s teenage daughter to help him hide her mother’s body before taking her and the toddler he had with Marshall to his father’s home in Georgia.