A 51-year-old Walnut Creek contractor has pleaded not guilty to charges that he held a day laborer captive and robbed him in a Lafayette house in October. Defendant Tod Morton appeared in a Walnut Creek courthouse Friday on felony charges of false imprisonment and second-degree robbery in connection with an Oct. 15 incident that police and prosecutors are describing as “bizarre.” Morton declined to speak to this newspaper after his arrest. His attorney, Michael Markowitz, could not be reached for comment Tuesday. Morton, who has no criminal record, picked up a 42-year-old day laborer outside a Concord hardware store and brought him to a house on Lucas Court in Lafayette, where he serves as a caretaker. The homeowners were out of town that day. Morton had the laborer do some yard work before bringing him inside to a storage room, where he instructed him to dust off wine bottles, and then left the room, senior deputy district attorney Bruce Flynn said.