Richmond Hill explosion: 7 keys that solved the Indianapolis case

Within hours of the Richmond Hill explosion, fire investigator Mario Garza and police detective Jeff Wager found themselves assigned to one of the largest — and most chaotic — incident scenes in the history of Indianapolis.

Two people — John “Dion” Longworth and his wife, Jennifer — were dead. A neighborhood was wrecked.

But why?

Garza and Wager spent weeks trying to answer that question. They leafed through debris, sifted dirt, managed hundreds of interviews and did some serious deductive reasoning. In the end, they figured it out. And five people went to prison.

Here are seven keys to the case that emerged from the Nov. 10, 2012, incident.

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Early suspicions

The ashes were still smoldering when Wager, a homicide detective with the Indianapolis Metropolitan Police Department, was assigned to investigate. Within four hours of the blast, Wager was hearing that Monserrate Shirley, owner of the home where the explosion originated, and her boyfriend, Mark Leonard, were conveniently out of town. Not just out of town but at a casino, where cameras would capture their image. It was a good alibi. Too good, it seemed to Wager. What raised his suspicions more, in the early hours, was Mark Leonard’s criminal record, including a prior arrest on insurance fraud charges.

Missing pieces

Garza, with the Indianapolis Fire Department, quickly ruled out some of the wilder theories behind the devastation. There was no evidence of a meth lab explosion, wayward fireworks or a drone strike. The Greenwood airport had not lost any planes. Just as important, the gas company had found no irregularities in the flow of gas into the neighborhood or leading up to the houses most affected. That only left a natural gas problem inside one of the homes. Missing in the rubble of the Shirley house were two key pieces: a device that regulates gas flow to appliances and a gas valve in the fireplace. Where were they?

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Searching high and low

In his quest for the gas fixtures, Garza left no stone unturned. He showed firefighters what he was looking for and sent them leafing through every piece of debris on the block. They searched on rooftops, in storm gutters and parked cars. Lawns were combed. When nothing turned up, Garza had excavation equipment brought in to dig 18 inches down into the soil around the Shirley house. Then the dirt was sifted. Nothing. No fireplace valve. No regulator. “I needed to find a logical reason why things weren’t the way they were supposed to be,” Garza said. “And I couldn’t find that reason.”

Peculiar habits

Everything Wager was learning about Shirley and Leonard only added to his suspicions. For three weekends leading up to the blast they had made trips to a riverboat casino. For three weekends in a row they had sent Shirley’s daughter to stay with a babysitter. And for three weekends in a row Shirley had boarded her cat, Snowball, with a groomer. None of it was criminal, but it was interesting.

Valuables insured, valuables missing

Wager learned that nearly a year before the blast Shirley had raised the insurance amount on the contents of her house to $300,000. She claimed to have expensive paintings in the home. Yet in the rubble of the house there were no remnants of artwork. In fact, there were no televisions, very little furniture, few personal items and almost no clothing. Even in an explosion, those such items don’t disappear. They are pieces of the debris. But in Shirley’s house, they were gone.

The microwave oven

Similarly, during an explosion, household appliances get tossed around, maybe even crushed. But Garza noticed the microwave oven in Shirley’s house was strangely warped. It looked as if it had exploded from the inside out, like a firecracker set off inside a soda can. Near the microwave was a metal cylinder that also appeared to have exploded. Nothing about a gas explosion would explain that.

Loose lips

If the evidence wasn’t stacking up high enough, police received a tip from a friend of Mark Leonard that he had bragged he was about to come into $300,000 and that he was surfing the internet for Ferraris. He also told friend Mark Duckworth that he and Shirley were about to move into an efficiency apartment. The big problem with that: Leonard said it a week before the explosion.

Two paths, one conclusion

The Richmond Hill investigation involved firefighters and police officers, federal agents and state agencies. It was left to Wager and Garza to put together all of the pieces.

For Garza, the case came down to the fact he was never able to find the gas regulator and the fireplace valve. They never turned up, he reasoned, because they had been removed purposefully to allow gas to build up in the house. The microwave, with its programmable timer, had been set to go off. The cylinder, most likely filled with a flammable fluid, had been placed inside the microwave. The explosion in the microwave ignited the gas in the house.

For Wager, the clues to the culprits were ample and as bright as neon signs. Confronted with the mounting evidence, Shirley agreed to plead guilty and testify against Leonard, who Wager said just wasn’t very smart. “All the things he did, the trail of it was there. All you had to do was look for it.”

When the arson investigator and the detective compared their findings, all the pieces of the puzzle fit together, forming a seamless explanation for the Richmond Hill explosion.

Two juries agreed, convicting Mark Leonard and his brother Robert Leonard Jr. in the conspiracy. Both are serving life sentences. Shirley pleaded guilty and received a 50-year sentence. An accomplice, Gary Thompson, received a 30-year sentence. Glenn Hults, who knew of the plot beforehand but failed to call police, received a three-year sentence.

Both Garza and Wager lament the greed that led to the crime. In the justice that was handed down, they say they found relief. And aside from their successful investigation, Wager said the pair came out with something else from the experience.

“Mario and I are good friends now.”

Call Robert King at (317) 444-6089. Follow him on Twitter and Facebook.

This article originally appeared on Indianapolis Star: Richmond Hill explosion: 7 keys that solved the case