From the Aberdeen Police Department:
Aberdeen Police Department Detectives have determined that the double shooting that occurred on Mt. Royal Ave in Aberdeen on Tuesday, April 7, 2015 was a murder–suicide.
The homicide victim, 56 year-old Linda Ota was taken to University of Maryland Shock Trauma on the morning of the shooting for treatment. She later died from her injuries on Wednesday, April 8th. Investigators have determined that her brother, 55-year-old Thomas Peterson shot her in the head before turning the gun on himself. He died of a self-inflicted gunshot wound on the morning of April 7th.
Detectives are still trying to establish a motive for the shooting.