"There's been a parallel investigation not only focused on the cause but also determining if there are individuals who have been responsible for this explosion and fire."
The owner of the home at 8349 Fieldfare Way, Moncy Shirley, was with her boyfriend at the Hollywood Casino when the explosion occurred.
Mark Leonard lives in the home and is acquainted with the man police are seeking.
Curry said investigators need information about a vehicle seen in the community that day.
"Specifically, if anyone has information about a white van seen in the subdivision on the day of the explosion and about the occupants of that van, we urge you to contact CrimeStoppers."
CrimeStoppers of Central Indiana is offering a $1,000 reward for information leading to an arrest. Federal authorities are offering a reward of up to $10,000 for information leading to an arrest and a conviction.
A neighbor told Fox59 News that he told police he saw a white van, similar to the one Leonard drives, parked in front of the home the afternoon of the explosion. Two men he did not recognize were seen walking away from the home.
Sources tell Fox59 that IMPD has impounded and searched a white van. Investigators also have the name of an acquaintance of Leonard's they'd like to speak with.
"That investigation has consisted of numerous interviews of witnesses as well as the execution of search warrants," said Curry.
One of those warrants was executed at the Cavalier Conference Center at US 31 and Thompson Road where Leonard supervises the shuttered motel for its owners.
Real estate documents uncovered by Fox59 News show photographs of the home and its contents when Shirley listed the property for sale in 2011.
Investigators have combed the rubble of the blast site, searching for evidence of shattered furniture.
Those documents also indicate that the home featured a gas furnace, water heater and fireplace along with an electric stove.
Homeland Security Chief Gary Coons has said the investigation is focusing on appliances inside the house.
Sources indicate that the gas meter to the home has been recovered. If it is undamaged, it could reveal if there was a spike in natural gas usage at the house in the hours before the explosion.
Mayor Greg Ballard said he attended the funeral of Jennifer and Dion Longworth, the neighbors who died in the blast. The mayor said it was hard for him to reconcile the pain of the couples' deaths.
"There is a search for truth and there is a search for justice," said Ballard.