Jurors get tutorial on natural gas as Richmond Hill trial continues

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SOUTH BEND, Ind. (June 17, 2015) - An employee of Citizens Energy Group told jurors in the Richmond Hill trial that shortly after arriving on the scene of a fatal natural gas explosion on Indianapolis' south side he noticed that a key component of the utility's fuel delivery system had been altered at the home of Monserrate Shirley.

Live blog: Go inside the courtroom with CBS4.

Paul Puckett testified that, "the Maxitrol regulator was missing."

Puckett, Citizens Energy Group Director of Shared Field Services, explained that such a valve, sometimes referred to as a step down regulator, is necessary to reduce the amount and pressure of natural gas that enters a house.

Investigators contend Mark Leonard and his co-conspirators disabled a regulator which is intended to keep dangerous levels of natural gas from entering into a home and that's what led to the fatal explosion.

The jury is being taken back to high school chemistry class today in day seven of Leonard's murder trial.

Jurors saw demonstration videos that protrayed what it looks like when a tabletop model home full of natural gas is ignited and what it sounds like when such a regulator is removed.

Richmond Hill resident Gloria Olvey testified earlier that she heard a hissing sound coming from Shirley's house hours before the explosion.

Leonard is accused of plotting to destroy girlfriend's house in an insurance fraud scheme that killed two residents and caused more than $4 million in losses to neighboring homes.

Prosecutors charge Leonard and two other men plotted the explosion by setting a timer on a microwave oven containing a small propane tank that clicked on several hours later on the night of November 10, 2012.

The State alleges 8349 Fieldfare Way exploded as a huge bomb, damaging or destroying 80 homes and that Leonard should have known that neighbors could be injured or killed even if that was not his intent.

Judge John Marnocha of St. Joseph Superior Court in South Bend, where the trial was moved to secure an unbiased jury, ruled that prosecutors would be limited in their use of a small propane tank as an example of the type of cannister that could be placed inside Shirley's microwave oven and exploded to set off the larger blast.

The judge noted that prosecutors indicated the original tank, if that was the true ignition source, was heavily damaged by the explosion though the remains of that cylinder are listed as an evidence item.

Indianapolis Fire Department (IFD) Lt. Mario Garza, the lead arson investigator, testified in the morning session and recounted the steps he took the night of the blast and in the days after to determine the cause of the Richmond Hill tragedy.

Puckett testified that the Richmond Hill explosion led to a "code red" designation and response by the local utility and that he responded to Fieldfare Way and began looking for utility company equipment at the scene and before long noticed that, "the regulator was removed and hard piping was put in its place."

Prosecutors contend Leonard and his half-brother Bob Leonard, Jr., and Gary Thompson conspired to disable the Maxitrol regulator which controls the excessive flow of natural gas into the house in order to introduce a large amount of fuel into the home for ignition.

Puckett testified that a Maxitrol regulator is the part of the delivery system owned and maintained by the homeowner.

As part of the chemistry tutorial, a gas meter was erected in the courtroom as jurors were allowed to sniff evidence display cards that approximated the scent of natural gas.

For the first time during the trial, Leonard appeared more animated, taking notes and engaging and smiling with his Defense team as evidence of the explosion was presented before the jury.

Yet to testify is another Citzens Energy Group employee who is expected to tell jurors that days before the blast, Leonard and his half-brother engaged him in a conversation at a southside bar, seeking information on the flamabilty of natural gas.

Dan Novak of the Indiana Utility Regulatory Commission explained a set of photographs taken of the gas pipelines and meters recovered along Fieldfare Way.

Novak said the meter from Shirley's house was in good shape and was the only undamaged meter among four such devices discovered at the scene.

The photographs indicated that two alterations were made to the natural gas system at Shirley's house: not only was the Maxitrol regulator missing and replaced by a hard piece of black pipe and a valve left in the wide open position to flood the home with natural gas, but a fireplace shut off valve was also missing.

After direct examination several jurors submitted questions that asked what skill level and tools would be necessary to remove such devices from the system.

"Anybody who understands a little bit of plumbing could do it," said Novak who indicated that research on the internet and access to a pipe wrench would be sufficient to alter the the system.

Thursday jurors will hear from a Citizens Energy meter reader who took the reading off Shirley's meter after the explosion that would indicate how much gas was used by the residents of 8349 Fieldfare Way in the last 15 days before the blast.