The Alaska man accused of killing five people at an airport in Fort Lauderdale, Florida, was raised in Puerto Rico and served in the National Guard there and in Alaska. Over the last year, relatives and authorities say his behavior grew increasingly erratic. Here is a timeline of key events in 26-year-old Esteban Santiago’s life.

— Dec. 14, 2007: Santiago joins the Puerto Rico National Guard.

— April 23, 2010: Santiago deploys to Iraq. He serves in an engineering battalion, fixing bridges and clearing improvised explosives from roads.

— Feb. 19, 2011: His stint in Iraq ends. Santiago’s mother says that while he was in Iraq he saw a bomb explode next to two friends. Relatives say he returned a changed man.

— November 2014: He becomes a member of the Inactive Ready Reserve and moves to Anchorage, Alaska, with his brother Bryan. He joins the Alaska National Guard.

He initially works at McDonalds, according to his brother, but later gets a job with a security company, Signal 88, making $2,100 a month.

— Jan. 10, 2016: Charged with assault and criminal mischief after his girlfriend reported that he smashed through her bathroom door, breaking the frame, and yelled at her. She also claimed that he tried to strangle her.

— Feb. 23: Santiago arrested, found in violation of terms of his release because he was at his girlfriend’s residence, where he was restricted from being.

— August 2016: Santiago’s stint in the Alaska National Guard ends. He was serving as a combat engineer in the Guard before his discharge for “unsatisfactory performance.”

— Oct. 21: Allegation of strangulation reported by his girlfriend. Investigating officers established no probable cause for an arrest.

— Nov. 7: Police called to Anchorage FBI office for a “mental health crisis” involving a man having disjointed thoughts. Investigating agents told officers Santiago arrived asking for help, was having “terroristic thoughts” and believed he was being influenced by the Islamic State. He was taken to a mental health facility. He had a gun with him that police confiscated. It’s not clear whether it was the gun used in the attack.

— Jan. 5: Santiago arrives to his flight four hours early carrying only a case with his Walther 9mm semi-automatic handgun in it, the Anchorage Daily News reported.

— Jan. 6: Santiago arrives at Ft. Lauderdale’s airport on a one-way Delta flight, and collects the gun he had checked. He goes into the bathroom, loads his gun and returns to the baggage claim area, killing five people, authorities say.

Jan. 17: A detention hearing is scheduled in his case.