Updated at 6:30 p.m. with details about a confession Mark Conditt recorded before his death and with new information about his possible cause of death.

PFLUGERVILLE — Mark Conditt joined the ranks of Ted Kaczynski and Eric Rudolph on Wednesday, the latest American “serial bomber” and likely the youngest such murderer to date.

For three weeks Conditt wreaked havoc on the Austin community, killing two and injuring four more, in a rash of attacks that ended Wednesday when he died, likely at the hands of one of his own explosive devices.

While the investigation is ongoing, police have confirmed Conditt recorded a 25-minute "confession" in which the 23-year-old bomber detailed his crimes and spoke of personal troubles.

"He does not at all mention anything about terrorism, nor does he mention anything about hate. Instead, it's an outcry of a very challenged young man," Austin Interim Police Chief Brian Manley said at a news conference Wednesday evening. "What was the motive? What was the reason? Sometimes we can't assign reason to irrational acts."

Conditt was described as rough by old friends, even intimidating. Online, he railed against homosexuality and defended the death penalty. And years before he terrorized the capital city, the self-described conservative even mused about terrorism.

"I think that it is just plain dumb to release a terrorist," he wrote online when he was 17, "no matter what."

As investigators continue to comb through central Texas towns for explosive devices Conditt may have left planted, they're still looking for more clues to make sense of the carnage he left behind.

‘No idea of the darkness’

Neighbors in the little corner of Pflugerville, about 30 minutes north of Austin, all had the same reaction to finding out the suspected bomber’s family lived in their backyard.

“Well, I’ll be damned.”

This is the “old side” of town, neighbors said, where people still live on streets named after ancestors who first settled this area 150 years ago. There’s only one way in or out — every other street leads to a dead end — so everyone that drives into their little corner of the world either lives here or took a wrong turn.

And yet few in the area knew much about the suspected bomber or his family. The Conditts were newcomers, comparatively speaking, buying the gray house on Pfluger Street about 15 years ago. On Wednesday morning, an American flag flew out front when FBI agent and Austin police showed up.

Just one neighbor out of a half dozen remembered much of anything about the Conditt family and their eldest son.

“They’re churchgoing people,” Jeff Reeb, 75, who lives next door, told reporters standing on his lawn. "They’re extremely good neighbors. I like them a lot. I’d call them an extremely nice, good people, nice family.”

Conditt's immediate family has not released a statement on the bomber's crimes or his death. An aunt who lives in Colorado told CNN they were "devastated" by the news.

“We had no idea of the darkness that Mark must have been in. Our family is a normal family in every way,” said the aunt, who identified herself as Shanee but did not give a last name. “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."

Family of the bomber’s victims hope Conditt’s death allows them to move on. Anthony Stephan House, 39, was killed by a package bomb left on his doorstep in northeast Austin on March 2. Draylen Mason was killed 10 days later. Mason, 17, was a gifted musician who’d been accepted to the University of Texas at Austin’s Butler School of Music. His mother was injured in the package bomb blast that killed her son.

Three others were also injured — Esperanza Herrera, 75, who likely received one of the bomber's packages in error, and two men in their 20s who were caught in a blast set off my a tripwire.

"We are a family of faith and we know that with God all things are possible," Mason's family said in a prepared statement, according to the Austin-American Statesman. "The most recent chain of events have brought some sense of closure that our beloved has received justice."

‘Rough around the edges’

Mark Conditt was the oldest child. He’d moved out of the family home few years ago, Reeb said, but lived just down the road in a blue and yellow house where bomb squads searched for homemade explosives Wednesday.

Conditt had two sisters — Christina, 21, a gymnast, and Sara, 18, who practiced martial arts — according to Facebook. Danene, his mother, posted a photo of him with a snowboard and another celebrating his graduation from high school in 2013. Her caption said he was considering going on a mission trip.

Danene Conditt homeschooled her children and often hosted Bible study and lunches after church, said Jeremiah Jensen, a high school friend who described Conditt as assertive and opinionated, even “intimidating.”

"When I met Mark, he was really rough around the edges," Jensen, 24, told the Statesman. "What I remember about him, he would push back on you if you said something without thinking about it. He loved to think and argue and turn things over and figure out what was really going on."

Conditt attended Austin Community College from 2010 to 2012. He left the college in good academic standing but did not graduate, a spokesman said.

A business administration major who took classes at both the Northridge and Round Rock campuses, Conditt previously worked in a gymnastics gym and repairing computers. For the last four years he worked at a semiconductor company before being fired in August, according to KVUE.

One of the few public clues into Conditt's thinking come from a blog he maintained for a government class he took when he was 17. Called "Defining My Stance," the blog is the home of half a dozen posts on everything from internet piracy to terrorism.

In these posts, Conditt advocated for the death penalty and against abortion. He criticized homosexuality and same-sex marriage.

“Homosexuality is not natural,” he wrote a month before his 18th birthday. “I do not believe it is proper to pass laws stating that homosexuals have 'rights.' What about pedophilia or bestiality?”

In a post opposing sex offender registries, he questioned putting people “on a list" for a crime committed as an "adolescent."

“So you have a guy who committed a crime,” Conditt wrote. “Will putting him on a list make it better? Wouldn't this only make people shun him, keep him from getting a job, and making friends?”

‘More credit than he deserves’

Serial bombers — single individuals acting on behalf of his or her own particular cause — are extremely rare in American history.

Enzo Yaksic, co-director of the Atypical Homicide Research Group at Northeastern University, said early comparisons to Kacyznski, the Unabomber, were misleading and gave Conditt “far more credit than he deserves.”

His varied and sophisticated tactics led some to believe he would be older, Yaksic said, because younger perpetrators may not be experienced enough to build bombs and sustain the motivation to do so. Yaksic had guessed the serial bomber would be 45 to 55 years old.

More than 500 local, state and federal law enforcement personnel worked on the case. Using surveillance video, cellphone data and Conditt's own car, police tracked the suspected bomber to a Round Rock motel. As they closed in early Wednesday, Conditt detonated an explosive device.

Chief Manley could not confirm whether his blast, or shots fired by police, ended Conditt's life. That's for the medical examiner to determine, he said, adding that the injuries he sustained from the explosion were significant.

“Conditt was undone by the electronic footprints he left behind which some might say was his way of letting law enforcement know that he wanted to get caught,” Yaksic said. “But a series of offenses like these can spiral out of the killer's control.”