As hundreds of thousands of people descend on Austin for the SXSW Festival, police have confirmed that they believe a serial bomber is on the loose. Interim Police Chief Brian Manley said Monday that evidence suggests that three package explosions that killed two people are related, the Austin American-Statesman reports. Manley said the bombs that killed 39-year-old Anthony Stephan House on March 2 and a 17-year-old boy on Monday arrived on doorsteps in "average-size" delivery boxes and exploded when the boxes were picked up or opened. Another bomb in east Austin on Monday injured a 75-year-old woman. A woman in her 40s was seriously injured by the bomb that killed the teenager.
Authorities say they haven't ruled out the possibility of the bombings being hate crimes. The Washington Post reports that the two people killed are relatives of prominent African American families in Austin. House is the stepson of former pastor Freddie Dixon, who says he knows Norman Mason, grandfather of the teenager killed Monday. Mason is a dentist who mentors African American athletes at the University of Texas, Austin. "I don't know who they’ve been targeting, but for sure, they went and got one of my best friends' grandson," Dixon says. "Somebody knew the connection." The woman injured by the second bomb Monday is Hispanic and police aren't sure if there is a connection between her and the other victims. SXSW organizers say they are "heartbroken" by the bombings and they are urging festival attendees to report anything suspicious, the AP reports. (Read more Austin stories.)