The news of the homicide investigation came the same day the victims, Dion Longworth and his wife Jennifer, were laid to rest.
Police say they are analyzing evidence, including appliances that may lead them to a cause.
Hundreds of mourners filled the St. Barnabas Catholic Church in Indianapolis for the funerals on Monday.
A short time later, investigators announced the blast that killed the Longworths and injured seven others may have been intentional.
Early in the investigation, the possibility of a gas leak or faulty gas lines was ruled out.
So, police say their focusing on finding a white van that was seen in the subdivision the day of the blast.
Dion's sister, Brookley, tells us she can't comment on the investigation, but she's thankful for Monday's showing of support.
"We don't know much. We know about as much as you guys do. They told us about, sometime this afternoon that they were going to release a press statement, so they let us know what they were going to tell you so we knew before they told you. We don't know anything you guys don't know," Brookley said.
Investigators say natural gas is to blame, they're just not sure what caused the explosion.
The prosecutors office says they're trying to determine if a high amount of natural gas was used the day of the explosion.
No arrests have yet been made.
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