Updated

A man accused of knowing about a plot to destroy an Indianapolis house months before a natural gas explosion leveled it in an alleged insurance fraud became the fifth person formally charged in that deadly 2012 blast.

A Marion County judge on Wednesday entered a not guilty plea for Glenn Hults, 48, who was charged with one count of conspiracy to commit arson in the explosion that killed two people, injured 13 and damaged or destroyed dozens of homes.

The judge also set an April 24 bond reduction hearing for Hults, who's being held on a $100,000 surety bond.

Prosecutors say the November 2012 explosion was a scheme to collect $300,000 in insurance and occurred when the home filled up with gas after a fireplace valve and a gas line regulator were removed. The blast killed a couple who lived next door.

Monserrate Shirley, her then-boyfriend, Mark Leonard, 46, and his brother, Bob Leonard Jr., 56, were charged in December 2012 with two counts of murder, arson and dozens of other counts in the explosion.

Shirley, 49, reached a plea deal in January under which she agreed to plead guilty to conspiracy to commit arson and testify against the Leonard brothers, and potentially others. Days later, a fourth person, Gary Thompson, 44, was charged with two counts of murder and dozens of arson counts in the explosion.

Prosecutors allege Thompson was offered $5,000 to burn down the home two weeks before the explosion, knew of subsequent plans to tamper with the home's natural gas flow and ignite the gas, and helped alter the gas line.

Prosecutors allege that Hults knew of the alleged explosion plot and warned Shirley about the dangers it posed.

"You're crazy, Bob Leonard is crazy, they are going to blow up the whole neighborhood," Hults told Shirley, according to a document from prosecutors.

The affidavit also states that Hults allowed Shirley's young daughter to stay at his home the night of deadly explosion, as well as the preceding two weekends when there were two failed attempts to first burn down and then blow up the home. Hults also allegedly agreed to safeguard some of Shirley's personal items she had removed from her home.

During all three occasions, Shirley and Mark Leonard left town and boarded the family's cat, prosecutors said.

Court documents say that Shirley and Mark Leonard told Hults at a July 4, 2012, pool party of their plans to burn down her home to claim damage for insurance money.

Hults allegedly told investigators that he recalled inviting the couple to that party but could not remember telling Shirley, at Mark Leonard's urging, how easy it would be to get insurance money by setting fire to her home.

Hults' attorney, Ralph Staples, said Hults may have spoken to the pair, but that doesn't mean he was a co-conspirator.

"Conversations are just that, just words. In order to prove conspiracy you have to have some intentional action. Knowledge isn't enough," Staples said.

Deputy Prosecutor Denise Robinson said Hults had encouraged Shirley to take part in the initial plan to set fire to her home scheme, and allowed her daughter to stay with him and his then-girlfriend on three consecutive weekends as the three plots played out.

Robinson said prosecutors "have corroborated some of those facts" and based on that decided they had probable cause to charge Hults.

"It's important to hold everyone accountable who were a part of what happened," she said.