GUAYANILLA, Puerto Rico - He grew up in Puerto Rico, played percussion in his high school band, spent nearly a decade in the National Guard, served as a peacekeeper in Egypt's Sinai Peninsula, worked as a police officer and then joined the U.S. Army.
That was Ivan Lopez's seemingly unremarkable route into the military. What happened from there - and why the 34-year-old soldier turned against his comrades with such deadly fury - were a mystery Thursday.
Investigators have been told that Lopez may have upset because the Army refused to grant him personal leave, CBS News has learned.
Authorities are also looking into reports that Lopez may have had an argument with a fellow soldier or soldiers before the rampage, and that he was being treated for mental health issues. But there were was still no specific motive known for Lopez's shooting rampage at the Army's Fort Hood in Texas, where he killed three people and wounded 16 others before committing suicide.
Some of those who knew him were baffled by the explosion of violence.
"He had a lot of friends. I never saw him fighting. He never seemed like a boy who had emotional problems," said Guayanilla Mayor Edgardo Arlequin Velez, who was also the leader of the school band that Lopez played in in this small, working-class town.
Lopez was sent to Iraq as a truck driver in 2011 during the final months of the war there. He came home complaining of a traumatic brain injury, according to military officials. But they said he did not see combat and was not wounded.
He sought help for depression and anxiety and was being evaluated for post-traumatic stress disorder, military officials said. But Army Secretary John McHugh said Thursday that a psychiatrist last month found no violent or suicidal tendencies. The soldier was prescribed Ambien for a sleeping problem.
He had no apparent links to extremists, McHugh said.
Glidden Lopez Torres, who is not related to the gunman but identified himself as a family friend speaking on behalf of the soldier's family in Puerto Rico, said Lopez's mother died of a heart attack in November.
Lopez was close to her and was apparently upset that he was granted only a short leave - 24 hours, later extended to two days - to go to her funeral, which was delayed for nearly a week so he could make it, the family spokesman said.
"That was a very frustrating time for him," said Yaritza Castro, who grew up with Lopez and now lives in Miami.
Castro said Lopez had two children from a previous marriage and a third with his widow. He took all three children to Disney World not long before his mother's death.
Castro said Lopez was a thoughtful person who called to check on her when her husband was deployed with the military, and he also sent care packages to her husband.
"He wasn't a monster. He was a very good person," Castro said.
Lopez's family was unaware he was receiving any treatment for mental problems, the family spokesman said. Lopez Torres said Lopez's relatives were devastated, trying to comprehend the shooting.
"He was a very laid-back person. I would even say a bit shy," Lopez Torres said. "That's why we are so surprised."Lopez grew up in Guayanilla, a town of fewer than 10,000 people, where small, well-kept houses are painted bright colors. The house he grew up in was empty Thursday. It is a one-story, concrete home painted white with green trim.
There are few jobs in the town, and many young people have joined the military in recent years. A young woman whose parents live in the town, 33-year-old Army Spec. Aleina Rodriguez-Gonzalez, was killed in Iraq in 2005.
The mayor described Lopez as somewhat introverted and passionate about music. His parents attended school functions, and they seemed close.In January, his wife, Karla Lopez, wrote "te amo," or "I love you," under a profile picture on a Facebook page believed to belong to Ivan Lopez. The picture shows him leaning back in a car, wearing dark sunglasses, with earphones hanging from his lobes.
The profile, under the name "Ivan Slipknot," includes photos of him in uniform and carrying weapons. Others appear to be family photos.Lopez spent four years at Fort Bliss in El Paso, Texas, before moving on to Fort Hood. In a statement, Fort Bliss officials said he served as an infantryman, with duties as a rifleman, grenadier and vehicle driver. Because of an unspecified "medical condition," he was reclassified as a truck driver.
In Killeen, Texas, where the family moved after Lopez was transferred to Fort Hood, neighbors in a three-story, blue and gray apartment building described him as friendly.
Shaneice Banks, a 21-year-old business management student who lives downstairs from the Lopezes, said her husband, who also works at Fort Hood, helped the family move in just three weeks ago. Hours before the shooting, Banks said, she ran into Lopez when he came home for lunch.
"They get an hour to come home," Banks said. "He was going to his car and I was like, 'Hey, how's your day going?' And he seemed perfectly fine. He was like, 'Day's going pretty good. I'll see you whenever I come back home.'"
After word came of a shooting at the base, Banks saw Lopez's wife frantically calling her husband over and over, trying to reach him via cellphone from the apartment courtyard.
"She was bawling because they have a 2-year-old and she was just holding the baby," Banks said. "My heart just went out to her. I was trying to get her information when I could, but she doesn't speak a lot of English. I told her, 'The last time you heard from him was like 3 o'clock. They could be shutting off the cellphone towers.' But of course that wasn't what happened."