During the first explosion early on Monday morning, the package was brought into the home before it detonated and killed the 17-year-old. Monday's first explosion happened at a home near the city's Windsor Park neighborhood and about 12 miles (20 kilometers) from the home where the March 2 package bomb killed 39-year-old Anthony Stephan House.
Police were processing the scene at the first Monday explosion when the second occurred.
Police officials now believe that the package bomb that killed a teenager and wounded a woman on Monday is linked to a similar attack that killed a man in another part of the city earlier this month. The Austin Fire Department said this incident also resulted from a package explosion, but police have not said whether it is connected to the other two explosions.
Mr Manley told reporters: "Early this morning one of the residents went out front and there was a package on the front door step". However, he emphasized that investigators have not linked any ideology or victim-targeting to the incidents, which all occurred at residences in different portions of East Austin. That could mean a package that wasn't expected, a package from someone you weren't expecting to receive a package from or a package that gives you cause for concern.
"We're not ruling anything out at this point", he said. A 17-year-old boy died Monday and a woman was transported with non-life-threatening injuries.
Officials say the teen found the package on the doorstep, took it inside and opened it in the kitchen, where it exploded.
The March 2 explosion, which happened shortly before 7 a.m. on Haverford Drive near an elementary school in northeast Austin, killed the man. Manley told the American-Statesman that authorities received several calls reporting the blast around 6:55 a.m. At the time, police said they believed it was an isolated incident. Because two of the victims were African Americans and one was Hispanic, Manley said, investigators also were viewing the attacks as possible hate crimes.
During a press conference this afternoon, Police Chief Brian Manley confirmed that APD believes the incidents are related and is asking residents to be hypervigilant of unexpected and/or unmarked packages.
"What we know is when the victims have seen these packages on the front porch, they have gone out and handled them in some way or another and have had the explosions occur", Manley said. However, they cannot say it's the cause.
In reference to speculation that the bombings were a spate of hate crimes, Manley added that investigators haven't identified a "specific victimology or ideology based on current evidence..."
According to Chief Manley, at least two of the packages were left overnight on doorsteps and discovered in the morning by the victims.