4th person faces murder charges in deadly house explosion

A man charged Thursday with murder and arson in a deadly Indianapolis house explosion was offered $5,000 to burn down the home two weeks before it was leveled by a natural gas blast, court documents allege.

Gary Thompson is the fourth person to be charged in the Nov. 10, 2012, blast that killed Dion Longworth, 34, and his wife, Jennifer Longworth, 36. The charges come days after homeowner Monserrate Shirley agreed to plead guilty to conspiracy to commit arson and testify against her former boyfriend, Mark Leonard, his brother, Bob Leonard, and potentially others.

Court documents allege Thompson was aware of a plot to tamper with the home's natural gas flow and set a timing device to ignite the gas.

Thompson, 44, faces two counts of murder, one count of conspiracy to commit arson and 34arson counts. Marion Superior Judge Shelia Carlisle entered a not guilty plea on behalf of Thompson Friday. She also appointed him a public defender, Heather Barton.

The judge granted Barton's request that Thompson be held separately from two other men charged in the case. Shirley is also charged.

Shirley and the Leonard brothers were charged in December 2012 with murder, arson and dozens of other counts. The explosion damaged more than 80 homes, several of which had to be razed.

Marion County Prosecutor Terry Curry said Shirley, 49, provided investigators with information that helped support the charges Thompson now faces.

Curry said Thompson, who was arrested Wednesday, has denied any involvement in the explosion.

Prosecutors have said the explosion was a scheme to collect $300,000 in insurance and occurred when the home filled up with gas after a gas fireplace valve and a gas line regulator were removed. A microwave, apparently set to start on a timer, sparked the blast.

Prosecutors said there were two previous attempts to destroy Shirley's home. Each time, Shirley and Mark Leonard left town and boarded the family's cat, they said.

Thompson told investigators he had worked for Mark Leonard for several years when Leonard offered to pay him $5,000 to burn down Shirley's home, according to a probable cause affidavit.

Leonard brought him a van with six cans of gasoline, but Thompson said "he became scared and did not set the fire," court documents state.

Although Leonard was angry the fire had not been set, Thompson said he nonetheless asked him days later to install a digital thermostat in Shirley's home, the documents show.

Shirley told investigators that after Thompson backed out of setting her home on fire, she saw him and Leonard working on the thermostat and the fireplace, according to the affidavit. Later, she saw them stuffing cardboard into the chimney "to prevent natural gas from escaping the house."

Thompson said Leonard had earlier installed a "cheap" thermostat but asked him to reinstall the original thermostat. Thompson said he then became aware that Leonard was considering using the "cheap" thermostat to create a spark to ignite natural gas, court documents state.

Thompson told investigators Leonard had asked him about natural gas, including how much "it would take to fill the house and reach a candle burning in the upstairs bedroom," the documents state.

He also said Leonard tried unsuccessfully to set fire to Shirley's home with natural gas the weekend before deadly explosion, according to the documents.

After that attempt failed, Thompson said Leonard asked more questions about natural gas and discussed using a microwave to create a spark.