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SOUTH BEND, Ind. (July 12, 2015)– More than two and a half years after Indianapolis was rocked awake by a late night explosion that ruined large parts of a south side neighborhood and took two lives, a jury will soon debate the case the State amassed against the man accused of plotting the fatal insurance fraud scheme.

Closing arguments are set for Monday morning in the courtroom of St. Joseph Superior Judge John Marnocha in the trial of Mark Leonard.

Leonard faces 53 counts, including two counts of murder and two counts of felony murder, for the explosion at then-girlfriend Monserrate Shirley’s house that damaged or destroyed more than 80 other homes leading to $4.4 million in losses and killing two neighbors.

Jennifer and Dion Longworth would have celebrated their 14th wedding anniversary last week.

Along with a laundry list of arson, conspiracy and insurance fraud counts, Leonard also faces two different types of murder charges, with different definitions, and the potential penalty of Life Without Parole in one of Indiana’s maximum security prisons.

“Well, there are two definitions,” Deputy Prosecutor Denise Robinson told reporters after the State rested its case Thursday. “Murder is the knowing killing of another human being. Felony murder simply says that while you’re committing another type of felony, a killing occurs, and that’s a distinction in the law.”

The distinction will lead Judge Marnocha to instruct jurors not only on the difference between the two capital charges, but also on a lesser included offense, reckless homicide, which an Indianapolis attorney not connected with the Richmond Hill case says may be Leonard’s best shot at receiving a prison sentence with the possibility of parole.

“Finding a way to demonstrate that the actual violence of this explosion is not a knowable thing,” is the best hope Leonard’s attorneys have, according to attorney John Tompkins. “The common knowledge that all individuals have does not relate to knowing exactly how many cubic yards of natural gas are needed to destroy a house versus destroy a neighborhood. It’s not something you could reasonably expect the average person to know and be able to calculate in their head.”

Prosecutors claim Leonard conspired with his brother Bob Leonard, Jr., and Gary Thompson to fill Shirley’s house with natural gas on the afternoon of November 10, 2012, and spark the blast with a delayed timer on a microwave oven set to go off at 11:10 p.m. with a metal canister inside.

Arthur Kirkpatrick, a former employee of Citizens Energy Group, testified the Leonard brothers quizzed him about the properties of natural gas the day before the explosion.

Witnesses and testimony confirmed the Leonards and Shirley tried and failed on at least two other occasions in the weeks before the blast to set off fires inside her home while the couple waited for word of the success of their plots at a riverside casino in southeast Indiana.

Steve Shand, a forensic chemist who investigated the explosion and was called to testify by the State, said the Leonards, in a sense, won the lottery, that their ill-conceived plan was such a long shot it should not have succeeded.

“They didn’t have a clue as to what they were doing,” he told jurors. “They got lucky.”

Shand said it took the right combination of natural gas and oxygen near the ignition site and the location of gasoline splashed inside Shirley’s house to create the bomb that rocked a large swath of Indianapolis and was heard in Johnson and Shelby Counties.

In February Leonard’s attorneys told prosecutors their client was ready to plead guilty to reduced charges that would still send him to prison but that proposal was rejected out of hand.

Tompkins said the defense may still succeed in winning a reduced sentence for their client.

“There are two ways to attack that,” he said. “They have charged him with something that he didn’t do because they overcharged it. ‘He did this. They charged him with that. You have to acquit him of what they charged him with even if you think he’s guilty of something he’s not charged with,’ or, they could ask for the lesser included. They could ask the judge to, say, instruct the jury on the lesser included and opt to try to get the jury to go that direction.”

That lesser included instruction will be given to the jurors Monday afternoon before they are sequestered in a downtown South Bend hotel to begin deliberations Tuesday.