A Columbia man charged in a double homicide is convicted of manslaughter. Cadilac Derrick, 37, was charged with two counts of first-degree murder, two counts of armed criminal action, second-degree domestic assault, and first-degree endangering the welfare of a child. His trial started Monday. On Thursday, a jury convicted Derrick of first-degree involuntary manslaughter, voluntary manslaughter, second-degree domestic assault and two counts of armed criminal action. He was found not guilty of endangering the welfare of a child.