Maryland State Police are investigating the second homicide at the Clifton T. Perkins Hospital in Jessup in less than a week.
A hospital staffer found 40-year-old Rogelio Mondragon unresponsive in his room about 6:30 p.m. Thursday. Hospital staff began to treat him and called 911.
Mondragon was pronounced dead at the scene.
Police said there was evidence Mondragon may have been in a fight. The medical examiner determined he died from multiple blunt force injuries to the face and neck.
Surveillance video showed 46-year-old Andre Mayo entering Mondragon's room twice within a half hour, police said. Mondragon was alone in the room each time.
Mayo was charged with first-degree murder and second-degree murder.
Saturday, officials said 24-year-old patient Vitaly Davydov killed his roommate, 22-year-old David Rico-Noyola. Davydov was placed at the facility following the 2006 murder of his Bethesda-based psychiatrist.
Perkins is a state mental hospital.