INDIANAPOLIS (Indy Star) -- The investigation into the Nov. 10 explosion that killed two people and damaged dozens of homes in the Richmond Hills subdivision is now a criminal homicide investigation that includes a hunt for a white van seen in the neighborhood before the blast, authorities announced tonight.

"At this time we're here to inform you that we're turning this into a criminal homicide investigation," Gary Coons, chief of the Indianapolis Department of Public Safety's Homeland Security division, told the media at anews conference.

Coons and Marion County Prosecutor Terry Curry did not take questions.

While the fire investigation has been progressing, there has been a parallel investigation, not solely focusing on the cause of the explosion but focusing on individuals who may have been responsible once accidental causes were eliminated. That investigation has consisted of numerous interviews with various individuals as well as execution of a number of search warrants and is being conducted jointly by the IMPD and the MCPO.

Based upon those interviews and results of those search warrants, that investigation is now considered an active criminal homicide investigation.

However, Curry said investigators are looking for tips, especially about a white van that was seen in the area before the explosion.

Officials also announced two rewards are being offered -- one for $1,000 from Crime Stoppers of Central Indiana and $10,000 from ATF - for information leading to the arrest and conviction of the person or persons responsible for the blast.

The announcement comes just over a week after the deadly blast, which damaged 81 of the 125 homes in the subdivision and flattened five more.

And it came just hours after the funeral of the two people killed in the blast: Dion and Jennifer Longworth, a couple in their mid-30s who lived in a home adjacent to the epicenter of the explosion.

Their funeral, which attracted hundreds of family members and friends, was held earlier today at St. Barnabas Catholic Church.

Authorities did not provide any information on possible targets of the probe, or say what makes them believe the explosion was a criminal act.

But under Indiana law, a murder charge could be filed in connection with the death of the Longworths if investigators find the explosion was the result of arson.

The law says "a person who ... kills another human being while committing or attempting to commit arson, burglary, child molesting, consumer product tampering, criminal deviate conduct, kidnapping, rape, robbery, human trafficking, promotion of human trafficking, sexual trafficking of a minor, or carjacking ... commits murder."

Much of the focus of the investigation so far has been on the home of Monserrate Shirley, 47, at 8349 Fieldfare Way, where the blast is believed to have originated.
Attorney Randy Cable, who's representing Shirley, said before the announcement that he and his client likely wouldn't comment on the announcement.

"I don't know what they're doing so I don't have any reaction," said Randy Cable, Monseratte Shirley's attorney. "My clients have been hounded to death and don't really have anything to say."

Shirley was out of town the weekend of the blast with her boyfriend, Mark Leonard, visiting a Lawrenceburg casino. Her daughter was staying with friends, and their cat had been boarded. Neighbors said a truck parked in front of the house for some time was moved on the afternoon of the blast.

Shirley told the Star last week she was in shock after the explosion, which investigators say caused an estimated $4.4 million in damage.

Shirley has said she doesn't know why her house exploded, and has denied assertions her ex-husband, John Shirley, made that the home's furnace was malfunctioning and could have caused the blast.

Shirley had said she was having problems with her home's heat several weeks ago, but that the thermostat had been replaced and the heat restored. Since then, she said, there hadn't been any other gas-related issues. She did say, however, that her daughter smelled something in the garage, which she thought smelled like gas. Shirley said she and Leonard could not smell it, though.

At a Nov. 12 news conference, Citizens Energy spokeswoman Sarah Holsapple said there had been no complaints about any furnace trouble at that home.

Meter readings taken in late October, Holsapple said, had also been normal.

Mark Leonard, 43, has a lengthy criminal record dating back to 1992. He has been convicted of several felonies, including intimidation, stalking, operating a vehicle while intoxicated with a prior conviction, theft, dealing in marijuana and possession of cocaine or a narcotic drug, according to Marion County court and Indiana Department of Correction records.

He was sentenced to nearly five years in prison for some of those offenses, according to department of correction. His projected release date for the most recent stint was in March 2009.

State Farm Insurance, which insured Shirley's home, according to her ex-husband, declined Monday to discuss details of their investigation. "We are not releasing any information about our investigation," said Missy Dundov, a State Farm spokeswoman.

In 2007, Shirley and her then-husband, John, filed jointly for Chapter 13 bankruptcy. Court records show they had liabilities of nearly $410,000 and assets of about $316,000.

Among their liabilities were two mortgages on the Fieldfare Way house, on which they owed a total of $225,794. The house's value was listed as $230,000, according to court records.

The house was listed for sale at $149,900 in late 2011 as a possible short sale, but it was pulled off the market in March at the request of the owner, according to real estate listings. The house had a gas furnace and a wood-burning fireplace with gas starter, according to descriptions.

The couple divorced in February 2011. According to divorce records, Monserrate Shirley, an intensive care nurse, assumed full responsibility for paying the home's mortgage, though John Shirley is required to pay $1,000 a month in child support.

Cable said as far as he knows, Monserrate Shirley is current on her mortgage payments.

Shirley's bankruptcy attorney, John Steinkamp, told The Star this week that the couple's bankruptcy case was dismissed because the Shirleys prematurely stopped making payments to the trustee. He said the timing of the dismissal coincided with their divorce.

According to the divorce settlement, Monserrate Shirley assumed sole responsibility for the Chapter 13 payment plan.

Police responded to a domestic disturbance at the Fieldfare Way home in February 2011, according to an Indianapolis Metropolitan Police Department report. John Shirley's then-girlfriend told police that Monserrate Shirley, 47, had assaulted her, according to the report.

Monserrate Shirley faced misdemeanor battery charges in March 2011 and a judge issued a warrant for her arrest, according to Marion Superior Court records, which still showed the case as open today. However, it's unclear whether those records are accurate; John Shirley told The Indianapolis Star that his girlfriend later declined to press charges against Monserrate Shirley.

In another incident in June 2011, John Shirley was accused of assaulting his girlfriend at the time, according to a police report. Court records confirm that confinement and domestic battery charges filed against him by the prosecutor later were dismissed.