Authorities continue to investigate a possible motive in the string of deadly bombings in Austin this month.

As CrimeOnline previously reported, Mark Anthony Conditt, 23, died after he detonated an explosive in her car as police were on his tail. According to a new report in the Washington Post, authorities are not certain that Conditt died as the result of the explosion or from police gunfire. An officer shot at Conditt after the suspect blew up his car, and authorities told the newspaper that the suspect was seriously injured in the explosion.

Police announced in a news conference Wednesday that Conditt has left behind a recorded 25-minute confession taking responsibility for the crimes, but did not specify where or how it was found. Conditt’s confession reportedly accounts for all of the known explosive devices found in the bombing spree, including the bomb in the suspect’s car, calming fears about the possibility of additional explosives left behind.

Interim Austin police chief ­Brian Manley said in the news conference that Conditt did not reveal a motive for the bombings in his recorded confession. The chief characterized the confession as “the outcry of a very challenged young man talking about challenges in his personal life that led him to this point.”

It is unclear what those challenges were.

The suspect’s grandmother, Mary Conditt, told the Washington Post that she was stunned by the events of recent days.

“We are of course grieving, broken and disappointed,” Conditt, 84, told the newspaper.

“I don’t know what else to say. . . . I know who Mark Anthony Conditt was to me, to his family, for all of his life, and this is not the Mark Anthony Conditt that we knew.”

The suspect’s grandmother confirmed that Mark had strong conservative-leaning views. As CrimeOnline previously reported, the suspect had created a blog as part of a community college project that included posts arguing that same-sex marriage should be illegal and that the sex offender registry should be abolished.

The victims killed by package bombs sent to their homes were both black males: 39-year-old Anthony Stephan House, and 17-year-old Draylen Mason, who reportedly died when he was shielding his mother from the blast. Another injured victim was Esperanza Herrera, who is 75 and Hispanic. The apparent racial component to the bombings have raised the possibility of hate crimes.

The Washington Post reports that the men who were killed were both from prominent black families in Austin, and had a family connection: House’s stepfather is a friend of Norman Mayson, Draylen’s grandfather.

A fourth and non-fatal explosion was a result of tripwire injured two people on Sunday night. The Washington Post reports that the explosive was placed in a predominantly white neighborhood, and that Conditt may have been targeting children who would have been walking to school the next morning.

Authorities are continuing to interview sources who knew Conditt in an attempt to determine a possible motive.

[Feature image: Mark Anthony Conditt/Facebook]