Following the shooting, police searched the gunman's home. There, they found a handwritten note purportedly penned by the gunman; Chief Burguan said that it referenced the gunman's relationship with the teacher, but was not a suicide note outside the context of the shooting. He also said that the note referenced "needing closure and feeling disrespected and dishonored". They also recovered a computer and a phone from the home. A man, later identified as the gunman's brother, was interviewed in police custody and later released. Dale Marsden, the superintendent of San Bernardino City Unified School District, promised a reexamination of North Park Elementary School's security measures. The shooting also prompted schools in Montana to reexamine their own security measures. On April 13, Marsden announced that fingerprinted volunteers will be the only non-staff members allowed into North Park Elementary, and that the school district will review a possible larger application of that rule in the future. Cedric Anderson (1963 – April 10, 2017), a resident of Riverside, was identified as the perpetrator. He was in a four-year-long relationship with Karen Elaine Smith, the slain teacher, but the two were only married from January to March. Their marriage ended by separation. At the time of the shooting, he was unemployed and attempting to start his own business. He had a criminal history of weapons charges, accusations of domestic violence, and drug charges spanning from 1982 to 2013, but no convictions ever resulted from those arrests. These charges predated his marriage to Smith. Before meeting Smith, Anderson lived around Atlanta, Georgia; Las Vegas, Nevada; and other cities in Southern California. In the late 1990s or early 2000s, he participated in an exposé by Las Vegas NBC affiliate KSNV on housing fees at Nellis Air Force Base. The report said that Anderson had been in the U.S. Navy for eight years and was married to a nineteen-year Air Force veteran who had been deployed to Pakistan. However, a military spokesman said that no one with Anderson's name appeared to have served in the Navy, according to official records. Anderson went on to post a video of the exposé on YouTube. Anderson's history of domestic violence accusations was extensively documented in filings obtained by the "New York Daily News". According to the filings, he had been married to another woman for eleven years before their marriage ended in 1996. In January 1997, the ex-wife filed a petition for a domestic violence restraining order against him. In the petition, she claimed that Anderson had threatened to kill her, their three sons, and himself, then later threatened to kidnap their children.