Twiggs had been through four tours in Iraq, one in Afghanistan and months of therapy for post-traumatic stress disorder in which he said he was on up to 12 different medications.
"He said, `Sir, I've served over there many times, and I would serve for you any time,' and he grabbed the president and gave him a big hug," said Kellee Twiggs, his widow.
About two weeks later, Travis Twiggs went absent without leave from his job in Quantico, Virginia.
He and his brother drove to the Grand Canyon, where their car was found hanging in a tree in what appeared to be a failed attempt to drive into the chasm.
The brothers carjacked a vehicle at the park Monday. Two days later they were at a southwestern Arizona border checkpoint, and took off when they were asked to pull into a secondary inspection area, Border Patrol spokesman Michael Bernacke said.
Eighty miles (130 kilometers) later, the car was on the Tohono O'odham reservation, its tires wrecked by spike strips.
As tribal police and Border Patrol agents closed in, Twiggs, 36, apparently fatally shot his 38-year-old brother, Willard J. "Will" Twiggs, then killed himself.
Pinal County Sheriff's spokesman Mike Minter said no motive has been established. But Kellee Twiggs said the decorated Marine would still be alive if the military had given him enough help.
"All this violent behavior, him killing his brother, that was not my husband. If the PTSD would have been handled in a correct manner, none of this would have happened," she said in a telephone interview from Stafford, Virginia.
Travis Twiggs, who enlisted in the Marine Corps in 1993 and held the combat action ribbon, wrote about his efforts to deal with post-traumatic stress disorder in the January issue of the Marine Corps Gazette.
The symptoms would disappear when he began each tour, he said, but came back stronger than ever when he came home.
He wrote that his life began to "spiral downward" after the tour in which two Marines from his platoon died.
"I cannot describe what a leader feels when he does not bring everyone home," he wrote. "To make matters even worse, I arrived at the welcome home site only to find that those two Marines' families were waiting to greet me as well. I remember thinking, 'Why are they here?"'
Weeks later, Twiggs "saw a physician's assistant who said that was the severest case of PTSD she'd seen in her life," his widow said.
He began receiving treatment, but the Marine wrote that he mixed his medications with alcohol and that his symptoms did not go away until he started his final tour in Iraq.
When he came home, "All of my symptoms were back, and now I was in the process of destroying my family," he wrote. "My only regrets are how I let my command down after they had put so much trust in me and how I let my family down by pushing them away."
Kellee Twiggs said her husband was "very, very different, angry, agitated, isolated and so forth," upon his return. "He was just doing crazy things."
She said her husband was treated in the psychiatric ward of Bethesda Naval Medical Center and then sent to a Veterans Administration facility for four months.
Most recently, Travis Twiggs was assigned to the Marine Corps Warfighting Laboratory at Quantico, a job he said helped him "get my life back on track."
"Every day is a better day now," he wrote in the Marine Corps Gazette. "... Looking back, I don't believe anyone is to blame for my craziness, but I do think we can do better."
Twiggs urged others suffering from similar problems to seek help. "PTSD is not a weakness. It is a normal reaction to a very violent situation," he wrote.
Kellee Twiggs said she cannot understand why her husband was not sent to a specialized PTSD clinic in New Jersey.
"They let him out. He was OK for a while and then it all started over again," she said.
A spokesman at Quantico, 1st Lt. Brian Donnelly, said the Corps is committed to providing full medical, psychological and social support to anyone with a combat-related injury, including PTSD.
"Our leaders are trained to be alert for signs of PTSD in their Marines and to provide a supportive climate in which Marines can feel comfortable seeking help," Donnelly said.
One lingering mystery in Twiggs' case is his older brother. Kellee Twiggs said she thinks the Louisiana man joined her husband in driving west "because T-Bo was hurting so bad and for so long that Will's life was a little in chaos."
"For them to both drive off into the Grand Canyon, they both apparently wanted to end their lives," she said.
Kellee Twiggs said "something needs to be fixed" in treating soldiers coming home from combat with PTSD.
"These boys and girls coming back, they need help, things need to be changed, and they don't need to be made to feel weak for asking for help," she said.