Its unclear whether he was shot by the FBI, or if he shot himself.
He was soon deemed a fugitive by US Marshals, as CBS Baltimore reported, with a warrant issued for his arrest.
After McGrath went missing, the US Marshals Service and the FBI teamed up to offer a $20,000 reward for information on his whereabouts.
Around 6.30 p.m. on Monday, FBI agents encountered McGrath at an intersection and opened fire, The Baltimore Banner reported, citing the FBI.
CBS News reporter Mike Hellgren posted pictures from the scene:In a statement Monday night, the FBI said it was reviewing an agent-involved shooting, the Post reported.