Joseph Newell Murder: Search for Antwan James, Md. man, who reportedly fatally shot his father, an off-duty cop, in yard work dispute

(CBS/AP) UPPER MARLBORO, Md. - Police say the stepson of a D.C. police officer shot and killed the off-duty officer during a dispute over yard work at their Maryland home.

Prince George's County police said Tuesday that they are searching for 27-year-old Antwan James. He's been charged in a warrant with murder in the fatal shooting of his stepfather, 46-year-old Joseph Newell.

Police were called to Newell's Upper Marlboro home Monday night and found him shot to death.  Police say Newell and James had been arguing over yard work before the shooting.

Newell had been with the Metropolitan Police Department since 1989.

Police are searching for James with K-9 units and other specialized officers. He is considered armed and dangerous.