After days of worry that a sophisticated "serial bomber" might be work in Texas' capital city, police say the man they believe is responsible is now dead. Here's what we know:

What has happened so far?

By Wednesday morning, five bombs had exploded in or near Austin — leaving two dead and several others injured. Using video and witness evidence, police were able to track down the suspected bomber at a Round Rock-area hotel. 

Police said the suspect was a 24-year-old white man, but didn't release any other information about him. Multiple reports said he was Pflugerville resident Mark Conditt, who records indicate was actually 23.

As officers waited for backup to arrive at the hotel, the suspect began to drive away. Police followed and he pulled off into a ditch on the side of the road. As officers approached, the suspect detonated a bomb inside his vehicle, killing himself. That appeared to end a month of fear for many Austin residents. 

The Texas Tribune thanks its sponsors. Become one.

The first three bombings happened in East Austin, an area of the city that has historically been home to black and Hispanic residents. The two people killed in the bombings — 39-year-old Anthony Stephan House and 17-year-old Draylen Mason — died on March 2 and March 12, respectively. Mason's mother was also injured.

Hours after the explosion that killed Mason, 75-year-old Esperanza Herrera also received an exploding package bomb. She was seriously injured but is expected to survive.

On Sunday night, a bomb exploded in a southwest Austin residential neighborhood, seriously injuring two people. Law enforcement officials said after that explosion that a sophisticated “serial bomber” might be at work in Austin’s capital city.

Then another package explosion happened Tuesday morning at a FedEx facility in Schertz, which is outside of San Antonio. Authorities said that package was headed for Austin.

Authorities have said there are similarities in the cases that led investigators to believe that the bombings were conducted by the same person. And FedEx confirmed in a statement Tuesday afternoon that "the individual responsible [for the package that exploded in its facility] also shipped a second package that has now been secured and turned over to law enforcement."

"We have provided law enforcement responsible for this investigation extensive evidence related to these packages and the individual that shipped them collected from our advanced technology security systems," the company said. 

The Texas Tribune thanks its sponsors. Become one.

As investigators were following those leads, an incident involving an "incendiary device" was reported at a Goodwill store in South Austin. Police rushed to the scene, only to find that someone had dropped off an old military artillery simulator there. The simulator ignited while being handled by an employee, but the incident was determined not to have anything to do with the bombings. 

What do we know about the alleged bomber?

Not much at this point. Reports indicate that Mark Conditt lived in Pflugerville and was homeschooled. He attended Austin Community College from 2010 to 2012 but did not earn a degree, an ACC spokesperson said. A neighbor described being shocked that Conditt was involved in the bombings, according to the Austin American-Statesman.  

Conditt kept a low profile on social media. The KVUE television station in Austin reported that he worked for Crux Manufacturing in Pflugerville. He started at age 19 and was let go last August because he wasn't meeting expectations, a company employee told the station. 

Texas Gov. Greg Abbott told Fox News that Conditt had roommates but that they were not believed to be suspects.  

What kind of bombs were being used?

The bombs that killed House and Mason and injured Herrera were packages left at doorsteps. Sunday’s explosion appears to have been triggered by a tripwire mechanism, police said, signifying a level of sophistication and perhaps randomness of targets that hadn’t been seen in the previous bombings. The explosion that happened Monday morning came in the form of a mailed package.

Police aren't saying what materials were being used, but there have been reports of shrapnel and, according to the Austin American-Statesman, the materials used to make the first three bombs were made up of common materials that can be bought at a hardware store.

What was the motive?

Police say they don’t know, but they're still investigating. 

"We will be here as long as it takes with our partners to figure out exactly what happened, why it happened and how it happened," an FBI agent said at a press conference Wednesday morning. 

The Texas Tribune thanks its sponsors. Become one.

Why aren't authorities releasing more information?

Police said they were keeping some things close to the vest about their investigation for a reason. They wanted to release information that could keep the community safe, but protect information that might be helpful for the investigation. 

Why? For one, they might have wanted to avoid the possibility of copycat bombings. By not disclosing the materials used in the bombs or other specifics, they could be more confident that subsequent bombings using similar bombs were done by the same person or people. Also, keeping certain details secret could have been helpful when interrogating a person of interest, since police could keep an eye out for information that hadn't been publicly divulged. 

Wednesday morning, the police were still searching for motives and investigating whether the bomber had any accomplices. More details should become available soon. 

Was race a factor?

The first three victims — House, Mason and Herrera — were people of color, which set off fears that the bombings might be racially motivated. However, the victims of the Sunday attack were white, leaving authorities at a loss over the motive of the attacks.

The latest package that exploded outside of San Antonio left one person wounded, a FedEx employee who suffered non-life-threatening "percussion-type" injuries, according to CBS News. The race of the latest victim is unknown at this time. It’s unclear who, if anyone, was the particular target of the bomb.

Why hasn’t this been deemed a hate crime or domestic terrorism?

Declaring something a hate crime requires knowing the bomber’s motive. And without a known motive, police say it’s premature for police to declare this a hate crime. Plus, Sunday’s explosion broke the pattern of the victims being people of color.

Same goes for domestic terrorism: It’s impossible to identify if you don't know the bomber's motive.

The Patriot Act classifies domestic terrorism as an attempt to "intimidate or coerce a civilian population; to influence the policy of a government by intimidation or coercion; or to affect the conduct of a government by mass destruction, assassination, or kidnapping." 

What has been the state and federal response?

Hundreds of law enforcement officers responded to the attacks. In addition to Austin police, more than 500 federal agents are working the case along with Texas Department of Public Safety troopers and bomb technicians from Houston and San Antonio.

On Sunday, interim Austin Police Chief Brian Manley announced a reward of $100,000 for information leading to the arrest of the person or people responsible. Abbott previously said that the Office of the Governor’s Criminal Justice Division is offering an additional $15,000.

Abbott also announced Monday that he was releasing $265,500 in emergency funding for Austin police to buy seven bomb-detecting X-ray systems.

“I want to ensure everyone in the Austin region and the entire state that Texas is committed to providing every resource necessary to make sure these crimes are solved as quickly as possible,” Abbott said.

On Monday evening, the San Antonio Police Department announced it was sending two bomb technicians and a bomb dog to Austin in wake of Sunday’s explosion.

On Tuesday, White House Press Secretary Sarah Huckabee Sanders posted on Twitter that President Donald Trump "mourns for victims of the recent bombings in Austin."

"We are monitoring the situation, federal authorities are coordinating w/ local officials," she wrote. "We are committed to bringing perpetrators of these heinous acts to justice. There is no apparent nexus to terrorism at this time."

Later, Trump called the bombings "terrible."

Who is covering the attacks?

The Texas Tribune — along with other local, statewide and national media — is covering is Austin bombings closely. Check out our Twitter list of reporters covering the explosions here.

Read related Tribune coverage: