On March 29, 2019, 41-year-old Alisa M Mayo of Hollis, New Hampshire, was found dead inside a residence on Deer Run Drive. Responding officers conducting a welfare check discovered Mayo and 51-year-old Brian McDonough; autopsy results show Mayo died of a gunshot wound to the head and her death was ruled a homicide by Chief Medical Examiner Dr. Jennie V. Duval.

McDonough also sustained a gunshot wound to the head, and his death was ruled a suicide. Investigators concluded McDonough shot and killed Mayo before taking his own life. Officials said the two were known to each other but did not publicly describe the nature of their relationship; with McDonough deceased, no arrests followed and authorities reported no ongoing threat to the public.

Mayo was a mother and a graduate of Hollis Brookline High School. If anyone knew Alisa, Brian, or their connection and has additional information, please share it.