Police say a man and woman were shot while walking their dog on a path behind Westlake High School in Waldorf Friday evening.
Police say a man walked up to the couple and opened fire. It appears to have been a random attack.
Teresa Ann Bass, 40, died at the hospital shortly after. Her husband, whose name will not be released, remains hospitalized in serious condition.
Katie O'Malley-Simpson of the Charles County Schools says there was a football game at Westlake, but there was no impact on the game.
A medical helicopter landed on school property to transport one of the patients because of the space available to land and its close proximity to the shooting scene,. O'Malley-Simpson says.
A neighbor tells ABC7's Richard Reeve at least two shots were heard.
Police say there is no known suspect or motive in the shooting. A reward leading to an arrest has tripled to $15,000.
The suspect is described to be a black man in his early twenties with a light complexion. Police say he's about 6'0 with a slim build and he may have short, curly hair.
"Anyone who knows our agency knows we will leave no stone unturned and will pursue every investigative lead to identify the suspect. We hope the increase in the reward will generate tips and we strongly encourage anyone with information to call our detectives or the Crime Solvers line. Callers can remain anonymous," said Sheriff Rex Coffey.