Three people have been arrested in the explosion on Indianapolis' south side that killed two neighbors and damaged dozens of homes.
Monserrate Shirley and her boyfriend, Mark Leonard, who lived in the home, along with Leonard's brother, Robert Leonard, were arrested on numerous charges, including murder and arson. John and Jennifer Longworth died in the blast.
All three were charged with two counts of murder, one count of conspiracy to commit arson, 33 counts of arson, a Class B felony and 12 counts of arson, a Class A felony.
The death penalty will be under consideration in the case.
Authorities believe that the the explosion was concocted in a financial scheme.
In a news conference late Friday morning, Marion County Prosecutor Terry Curry said the source of the blast was a microwave oven and detailed what is included in the probable cause affidavit.
Curry said that the microwave oven had exploded from inside out and that was the point of ignition.
Also, a natural gas step-down valve into the home had been removed and a gas valve in the fireplace was missing.
Investigators said, it took six to nine hours for the house to fill with enough gas to cause that kind of explosion.
Investigators say that the gas flow would have had to have started around mid afternoon for the gas to reach the volume of the explosion that happened at 11 p.m.