FRANKLIN COUNTY, Va. – The FBI and the US Marshals Service have now joined the search for the Franklin County Marine wanted for the murder of his mother’s live-in boyfriend, Rodney Brown. The Marine Corps confirms that the Naval Criminal Investigative Service is also helping local authorities in their efforts to locate Michael Alexander Brown, who is wanted for second-degree murder and firearms charges in Saturday’s shooting death.

Local authorities say that while the focus of the search is in Virginia and North Carolina, they think 22-year-old Michael Brown could be on the move, and may have fled the area. He was last seen on surveillance photos taken at a Franklin County store on Saturday.

Authorities are still trying to establish a possible motive but neighbors say they believe Michael Brown recently learned that Rodney Brown wasn’t his father, contrary to what he had believed for much of his life.

Michael Brown deserted Marine Corps Base Camp Lejeune in North Carolina last month.