A Lancaster County man has been charged in connection with the death of his 3-month-old son.Rolston Sturkey, 30, was charged with involuntary manslaughter, endangering the welfare of a child and drug offenses.According to court documents, Sturkey smoked marijuana while taking care of his son last September in an apartment in Lancaster Township.Sturkey told police he made a bed out of blankets on the floor and laid the infant down about six inches from his chest, the criminal complaint alleges. Sturkey said that when he was awakened the next morning, the baby wasn’t breathing.Investigators said the infant died of asphyxiation as a result of co-sleeping with Sturkey.