(CNN) Mark Anthony Conditt's family said they home-schooled him and worked hard to raise him right. But authorities said he was a "very challenged young man," who confessed to building and setting off a series of bombs that terrorized central Texas for three weeks.
The Austin serial bomber killed himself when he detonated one of his bombs early Wednesday. He was responsible for six other devices, five of which detonated, killing two people and injuring five others.
Federal agents found bomb-making material in a house he shared with roommates in Pflugerville and said he recorded a video confessing to the crimes.
The idea that Conditt could be a skilled bomb maker seemed unthinkable to his grandmother, Mary Conditt. He was quiet, kind, and she'd never seen any signs of malice and violence in him, she recalled.
"We had no idea of the darkness that Mark must have been in. Our family is a normal family in every way," said an aunt, Shanee, who declined to give her last name, in a family statement.
In a phone interview from Colorado, Mary Conditt said: "If anything, he's low-key and peaceful."
She said the 23-year-old Conditt was "from a family that is so tight, that works so hard to raise their children correctly. It's just horrible." He finished his home-schooling and was "looking forward to figuring out what most kids are -- figuring out his life and visiting his family and being close to them," she said.
Shanee said the family was "devastated and broken at the news that our family could be involved in such an awful way."
"We love, we pray, and we try to inspire and serve others. Right now, our prayers are for those families that have lost loved ones, for those impacted in any way, and for the soul of our Mark. We are grieving and we are in shock," she said.
She said she last saw Conditt over the Christmas holiday.
"Christmas was wonderful. We played cards. We laughed, we went to shows together," she said.
Interim Austin Police Chief Brian Manley said Conditt's 25-minute confession video doesn't shed light on his motive.
"We're never going to be able to put a (rationale) behind these acts," Manley said.
"He does not at all mention anything about terrorism, nor does he mention anything about hate," Manley said. "But, instead, it is the outcry of a very challenged young man talking about challenges in his personal life that led him to this point."
Conditt attended Austin Community College from 2010 to 2012 but did not graduate, according to school records, said spokeswoman Jessica Vess. He declared business administration as his major and took general education courses.
In 2012, he created a blog for a US government class project, according to the college. In the blog, which focused on national government topics of the time, Conditt gave his opinion opposing same-sex marriage and free abortions while he supported the death penalty and eliminating sex offender registries.
Surveillance photos confirmed by police showed Conditt wearing a baseball cap over long blond hair as he dropped off packages in a mail delivery office in Sunset Valley, southwest of Austin
This week, authorities received information that led them to Conditt as a person of interest, and he later became a suspect.
They later identified his car and spotted it Tuesday night at a hotel in Round Rock, a few miles north of Austin.
As officers waited for tactical units to arrive on the scene, Conditt began to drive away and then stopped on the side of the road.
SWAT officers approached the vehicle and Conditt detonated a bomb inside his car, Manley said.
Conditt died inside the vehicle.
Hours later, at an evening news conference, Austin Mayor Steve Adler said the community had been anxious.
"I'll tell you that I think our community was getting a little afraid here ... toward the last few days."
Gov. Greg Abott said Austin police were meticulous as they tried "to locate and apprehend -- if possible alive -- the treacherous, evil criminal who committed these acts."
This story has been updated to correct Mark Anthony Conditt's age to 23, based on public records. Earlier, police identified the suspect as a 24-year-old man.