Esteban Santiago-Ruiz (born March 16, 1990), a -year-old resident of
Alaska, unemployed, and a former
Alaska Army National Guard and Puerto Rican National Guard member, was arrested immediately after the shooting. Santiago flew on a
Delta Air Lines flight from
Ted Stevens Anchorage International Airport in Alaska, connecting through
Minneapolis–Saint Paul International Airport. Investigators say that he declared a 9mm pistol with two magazines, locked in a secure container, his only checked baggage. He retrieved it in Fort Lauderdale and loaded the gun in the airport bathroom just before the attack. Santiago was reported to be carrying
military identification at the time of the shooting. Santiago was born in
New Jersey in 1990 and moved to
Puerto Rico two years later. He lived most of his life in
Peñuelas, Puerto Rico, and attended high school there. He joined the
Puerto Rico National Guard on December 14, 2007, and served in the
Iraq War from April 23, 2010, to February 19, 2011, as a
combat engineer. He served in the
Alaska Army National Guard from November 21, 2014, until August 16, when he received a
general discharge for "unsatisfactory performance." He began to suffer mental illness after his tour in Iraq; according to his family, he was severely affected by seeing a bomb explode near two of his friends while in service. He had received psychological treatment shortly before the airport attack. The
Puerto Rico Police opened an investigation into his erratic behavior and confiscated his firearms in March 2012. They were, however, returned to him in May 2014. He also obtained a Florida
driver's license in August 2012 even though he never lived in Florida, per official records. He provided the license on his successful application for
permission to carry a concealed gun in Puerto Rico. While in Alaska, Santiago worked as a security guard for a private company, In January 2016, Santiago was arrested and charged with assault in an incident involving his girlfriend in
Anchorage, Alaska. Police alleged that Santiago yelled at her, broke down the door, and choked her. The case resulted in a
deferred prosecution agreement, and a domestic violence temporary protection order had expired. Santiago was subsequently scheduled to appear by telephone for sentencing in the domestic violence case in mid-April 2017. Santiago visited the
FBI field office in Anchorage in November 2016, telling the FBI that the
U.S. government was controlling his mind and making him watch online videos by the
Islamic State of Iraq and the Levant, and that he was being forced to join that group by the
CIA. He said that he was hearing
voices in his head telling him to commit acts of violence, but he also said that he was in control and did not intend to hurt anyone. The FBI urged him to seek mental health treatment, and notified the local police who detained him and took him to a medical facility for a mental health evaluation. He was later investigated by the FBI, which discovered no links to terrorism or any violation of laws occurring during the Alaska incident. Alaska police took his handgun from him due to the incident and held it for 20 days before returning it in December because Santiago had not been convicted of a serious crime, involuntarily committed to a mental institution, or adjudicated as
mentally defective. ==Investigation==