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SOUTH BEND, Ind. (June 29, 2015)–For the first time, jurors in the Mark Leonard trial heard evidence tying the defendant to the fatal explosion that rocked Indianapolis’ south side in 2012, but didn’t learn about an alleged affair by his girlfriend that led to, “blackmail,” and, “hush money.”

Live blog: Go inside the courtroom with FOX59.

An Indianapolis Fire Department (IFD) arson investigator testified that witnesses told him Leonard expressed an interest in blowing up Monserrate Shirley’s house in the weeks before the explosion.

Moncy Shirley2
Monserrate Shirley

Before jurors arrived to begin the fourth week of the double murder trial in a South Bend courtroom, defense attorneys argued they should be able to put evidence of a Shirley extramarital affair on the record.

An investigator also told the jury that he found evidence of gasoline poured onto the floor of the leveled Shirley home in the Richmond Hill community during his probe.

Shirley is expected to testify later this week against her ex-boyfriend who is accused of leading the plot to blow up her house with natural gas as part of an insurance fraud scheme.

Two neighbors died and 80 homes were damaged or destroyed at a loss of $4.4 million on the night of November 10, 2012.

Defense Attorney Diane Black alleged that Shirley had conducted an affair and “received payment and hush money,” for keeping quiet about the liaison.

Dianne Black (Sketch by Dave Blodgett)
Diane Black (Sketch by Dave Blodgett)

Shirley was “blackmailing the doctor,” according to Black, belying the contention that the woman at the center of the ill-fated plot, “has no will of her own and cannot manipulate,” however, evidence of the affair shows she can manipulate, “for financial gain.”

St. Joseph Superior Judge John Marnocha ruled that testimony about Shirley’s alleged affair spoke to her character, not her complicity in the conspiracy, unless the prosecution raised character issues during her anticipated testimony and would not be permitted into evidence.

“Whether she has had one affair or ten affairs or a hundred affairs,” said the judge, “does not say anything at this point.”

The judge also approved transportation orders for two incarcerated offenders to house those potential witnesses at the St. Joseph County Jail over Prosecution questions regarding the relevance of their testimony to the trial.

Lt. Mario Garza, lead IFD arson investigator, told jurors he quickly determined that the origin of the blast that obliterated Shirley’s house came from inside the residence as evidenced by the damage to anchor bolts in the structure.

Mario Garza
Mario Garza

Garza said as he picked through the debris of 8349 Fieldfare Way he noted the absence of wrecked television sets, which he would expect to find as the Prosecution is attempting to paint a picture of arson and the propensity of conspirators to remove personal items of value.

Glenn Hults, the fifth co-conspirator to be charged, is alleged to have offered to secure Shirley’s personal possessions that were removed from the home before 11:10 p.m. the day of the explosion.

Garza said he quickly ruled out the home’s hot water heater, furnace and fireplace internal piping as the cause of the blast due to their relatively undamaged conditions.

Richmond Hill damage
Richmond Hill damage

The investigator said he found a heavily damaged microwave oven and an exploded metal canister in the debris pile associated with Shirley’s kitchen.

“It was my opinion that there was an internal force that pushed the microwave components in an outward condition,” said Garza. “The easiest way to say it is, ‘Something exploded in the microwave.'”

Garza also explained once again the properties of natural gas for the jury and the perfect gas/oxygen mixture for ignition would have to fall in the 5-15 percent range would not have been uniform throughout the house at the time of the blast.

“I think that is something that even someone without training would know that this house exploded shortly after eleven o’clock.”

Also introduced into evidence was the recovered operator’s manual associated with the oven that listed instructions on setting a time delay on the appliance.

Bob Leonard, Jr.
Bob Leonard, Jr.

Prosecutors contend that Leonard’s half-brother, Bob Leonard, Jr., and Gary Thompson entered the Shirley home earlier that afternoon and disabled  two natural gas control valves to fill the home with fuel and then set a delayed timer on the microwave oven to explode a metal canister within it and spark the explosion.

“You put something in a microwave it is going to spark and arch and be an ignition point,” testified Garza who said he spent 20 days in the Richmond Hill community looking for evidence.

Garza also identified a photograph of the home’s gas manifold attached to the external gas meter with a piece of black pipe that replaced a step down regulator and indicated it would have been intentionally placed to bypass the valve as it, “would be impossible,” for the device to blow up and reassemble itself.

The description led to a wave of laughter from the jury.

Garza told jurors that he determined the cause of the Richmond Hill blast and fire to be intentional.

A month after the blast investigators discovered photographs from a real estate Multiple Listings website, first reported by FOX59 News weeks before, and compared the items depicted with wreckage found and not found at 8349 Fieldfare Way.

Photo of the Shirley home from a real estate website
Photo of the Shirley home from a real estate website

Facing the jury, Garza testified that he was unsuccessful in finding depicted items including a frame surrounding a photograph of Shirley’s daughter.

Shirley had attempted to sell her home in the summer of 2011 as her financial picture worsened amid an unsuccessful bankruptcy filing.

Garza said that core samples taken from the home’s concrete foundation found evidence of gasoline in the kitchen and living room areas.

Mark Duckworth told Garza he had a conversation with Leonard about whether a “tsunami wind” down the chimney could ignite the fireplace and Arthur Kirkpatrick, an employee of Citizens Energy Group, told investigators he met the Leonard brothers in a bar and where they asked him how much natural gas it would take to fill a home and what was the function of a regulator in controlling the introduction of fuel into a residence.

Mark Leonard (left) and Defense attorney David Shircliff (right) in court. (Sketch by Dave Blodgett)
Mark Leonard (left) and Defense attorney David Shircliff (right) in court. (Sketch by Dave Blodgett)

Garza said those accounts dovetailed with the theory he had already developed into the origin and cause of the explosion.

Attorney Black tried to shake Garza on specific evidence regarding the amount of natural gas inside the Shirley house at the time of the blast.

“The bottom line is there was a lot of gas in that house and there were ignition sources in the house,” said Garza who contended minor variations in the amount of fuel in the residence would not change his underlying theory.

Garza admitted that there were several potential ignition sources in the Shirley house that night, including chafing dishes, the furnace, the water heater, incense sticks, candles, the refrigerator, any electronic device with a spark, including a microwave oven, and even static electricity.

“You’re kind of stretching it there,” answered Garza to chuckles in the courtroom.  “If there’s nobody in the house, I don’t know how you would get static electricity.”

Upon re-direct examination Garza said, “If you want to make sure the job gets done, you’re going to put in as many as you can,” when he was asked about the possible multiple ignition sources.

When Black tried to elicit testimony that multiple ignition sources could be proof of an attempt to set an intentional fire, Garza said, “When you intentionally release gas into a house, the intention is more than just setting a little fire.”

As an indication of the jury’s grasp of the complexities of the mechanics of natural gas flow, one juror asked whether there would ever be a legitimate reason to remove a Dante valve from a fireplace.

“There’s no logical reason to remove it since it is the only safety valve in the fireplace,” said Garza who explained the valve is a shut off device and not a regulator.

Black determined that the operator’s manual for the Shirley microwave listed a 24-hour time delay feature, indicating the earliest the timer could have been set was the previous night at eleven o’clock, “and you’re aware Mark Leonard was at the casino and not around his house on Friday night.”

Garza agreed as investigators determined Leonard and Shirley awaited word of the success of their alleged plot at the Hollywod Casino in Lawrenceburg, returning to Indianapolis after a neighbor’s phone call informed them of the explosion.

IMPD Homicide Sgt. Jeff Wager testified that at the time of the explosion, Brooke Shirley, was staying at the home of Hults and the family cat, Snowball, was being housed at Barkerfeller’s Kennel.

The final witness of the day was Travis Bell, a disc jockey at the Hollywood Casino, who told jurors that the night of the explosion, Leonard invited him to meet Shirley at the resort’s premier bar and asked the entertainer to announce the couple was celebrating its anniversary.

Bell said he did not know Leonard though the defendant claimed to know him from attending high school on Indianapolis’ south side, but he did know Bob Leonard, Jr.

In attendance at the morning hearing was Mark Inman, the public defender appointed to represent Bob Leonard, Jr., who will go on trial in a Fort Wayne courtroom early next year.

Conspiracy evidence in this trial will be replicated in his case. Also in the gallery was Bob Hill, the Chief Public Defender in Marion County.

Shirley is already at the St. Joseph County Jail, having been transferred from the segregation unit of the Marion County Jail where she has resided since her arrest just before Christmas of 2012.

The single mother, held without bond and potentially facing decades in prison after agreeing to plead guilty to reduced charges, is expected to take the witness stand Wednesday in the most spectacular criminal conspiracy case in Indianapolis history as she prepares to testify against her former lover and explain to jurors why her daughter and cat were not at home the night their house blew up.

“The fire investigation answers questions for the jury, hopefully, how it was done,” Deputy Prosecutor Denise Robinson told reporters outside the St. Joseph County Courthouse, “but now that we’ve answered how it was done, we’re into who did it and that’s where we start to go at this point.

Denise Robinson (Sketch by Dave Blodgett)
Denise Robinson (Sketch by Dave Blodgett)

“We know there was an ignition source. If there wasn’t an ignition source, the house wouldn’t have blown up. When we talk about potential ignition sources, because the house did blow up, we can’t say with certainty this is one. We found wreckage of several in the explosion and that satisfies the requirements.”

Robinson discounted the Defense attempt to raise allegations of Shirley’s affair, responding that there was no evidence to support one of the contentions regarding “blackmail” and “hush money.”