The Richmond Hill Explosion: The Insurance Scam That Leveled a Neighborhood

At about 11:10 PM on November 10, 2012, the house at 8349 Fieldfare Way in the Richmond Hill subdivision of Indianapolis ceased to exist. The blast — investigators later compared its force to roughly three tons of TNT — was felt three miles away. It shattered the quiet of a gated southeast-side neighborhood where, as one resident put it, everyone was "all best friends."

Next door, at 8355 Fieldfare Way, John "Dion" Longworth, 34, and his wife Jennifer, 36, a beloved second-grade teacher, were home. Neither survived. Seven neighbors were injured, roughly 200 people were forced out overnight, and 33 houses would eventually be condemned and demolished. Damage topped $4 million.

For the first hours it looked like a catastrophic accident — a furnace, a gas leak, terrible luck. Then investigators started asking why the house at the center of the crater had been so conveniently empty.

The setup: an empty house on a full street

The home belonged to Monserrate "Moncy" Shirley, a nurse, who lived there with her boyfriend, Mark Leonard. On the night of the explosion, the house was strategically vacant:

• Shirley and Leonard were away at a casino hotel.
• Shirley's daughter had been sent to stay with a babysitter.
• Even the family cat had been boarded.

That pattern — every living thing removed from a house that then exploded — is the kind of detail an arson investigator reads like a headline. So was the paper trail: in the months before the blast, Shirley's homeowner's insurance had been increased to roughly $300,000.

The evidence: a bomb built from a kitchen

The Bureau of Alcohol, Tobacco, Firearms and Explosives worked the crater alongside Indianapolis investigators, and what they reconstructed was not a leak but a machine:

• The gas. A valve on the fireplace had been removed, letting natural gas pour into the house for hours until the structure was effectively a bomb with drywall.
• The trigger. The remains of a microwave oven told the rest of the story — prosecutors said its 24-hour delayed-start feature was used to set off the blast with a metal container inside, giving the conspirators a full day of distance and alibi.
• The dry run. Evidence at trial showed the scheme had been attempted before — a prior weekend when the house filled with gas but failed to ignite — before the fatal attempt succeeded.

It was, in effect, a timed demolition executed in the middle of a sleeping subdivision — by people who had done the math on the insurance payout and never bothered with the math on the blast radius.

The trials: three verdicts and a plea

The investigation moved from accident to homicide within weeks, and by December 2012 Shirley, Mark Leonard, and his half-brother Bob Leonard were charged with murder and arson.

The case broke open in January 2015, when Shirley flipped — pleading guilty to two counts of conspiracy to commit arson and agreeing to testify against the Leonard brothers. Her testimony put the plan squarely on Mark Leonard: his idea, his mechanics, his brother executing the final attempt.

• Mark Leonard was convicted in July 2015 — after a venue change, by a jury that heard weeks of forensic and financial evidence — on more than 50 counts, including two counts of murder. Sentence: two consecutive life-without-parole terms plus 75 years. While awaiting trial, he also tried to hire a hitman from jail to kill a witness; that earned a separate conviction and another 50 years.
• Bob Leonard, tried separately, was convicted on the full slate and sentenced to two consecutive life-without-parole terms plus 70 years.
• Gary Thompson, a friend charged for his role in the scheme, received 30 years with 10 suspended.
• Monserrate Shirley was sentenced in December 2016 to 50 years — the maximum her plea agreement permitted. The judge was not persuaded that cooperation erased culpability: it was her house, her insurance policy, her neighborhood.

Where they are now

Mark Leonard died in prison on January 30, 2018, at age 48 — of natural causes, per the Marion County coroner — barely two and a half years into a sentence designed to last several lifetimes. Bob Leonard remains in prison for life. Shirley remains incarcerated; inmate records put her earliest possible release in the mid-2030s, when she will be in her seventies.

The Longworth family buried a son and a daughter-in-law. Richmond Hill rebuilt — slowly, house by house — around a scar where a third of a street used to be.

What the cameras caught

Netflix's Worst Neighbor Ever (released July 1, 2026) devotes its episode "Midwest Meltdown" to Richmond Hill, and the case is a natural fit for a series built on recorded evidence: the night-of emergency response, the fire that swallowed two more homes before crews could reach them, and the trial exhibits — including scene photographs and the microwave's remains — that turned a "gas accident" into more than 50 guilty counts.

This is the kind of file this channel exists for. Nobody confessed on the night. The neighborhood's own security cameras, the ATF's crater forensics, and a paper trail of insurance documents did what no witness could: they proved that the explosion wasn't something that happened to Richmond Hill. It was something aimed at it.

For the other three cases in the series, see our full breakdown of every case in Worst Neighbor Ever.

Case status as of this writing: all four conspirators were convicted or pleaded guilty; Mark Leonard died in custody in 2018, Bob Leonard is serving life without parole, and Monserrate Shirley remains imprisoned on a 50-year sentence. This article is based on trial evidence as described in court, public records, and contemporaneous reporting. Photo: the night of the explosion, November 10, 2012 — State's Exhibit 8, as shown in trial coverage.