This is an archived article and the information in the article may be outdated. Please look at the time stamp on the story to see when it was last updated.

INDIANAPOLIS (Jan. 28, 2015) – A fourth person has been charged in connection with the November 2012 explosion that killed two people and damaged or destroyed dozens of homes in the Richmond Hill subdivision on the south side of Indianapolis.

Gary Thompson, 44, is charged with two counts of murder in connection with the blast, FOX59 has learned. He has been arrested and formal charges are expected Thursday.

Dion and Jennifer Longworth died in the house explosion. Three people–Monserrate Shirley, Mark Leonard and Bob Leonard–were charged in the case. Shirley agreed to plead guilty last week to two counts of conspiracy to commit arson. Mark Leonard faces a June trial in St. Joseph County.

Prosecutors said Shirley and the Leonard brothers set off the blast in a scheme to collect insurance money.

Thompson’s neighbors say they are troubled by the arrest.

“He lives so close and it damaged so many homes and peoples lives. How do you do that?, asked Connie Caruthers.

For more than two years, detectives and prosecutors have theorized that that the Leonard brothers hadn’t carried out the scheme on their own. While Mark Leonard was at a casino with Shirley that weekend, witnesses reported seeing  Bob Leonard and another man leaving the home on Fieldfare Way on the afternoon of the blast.

Last week, defense attorney Jim Voyles told the court Shirley would plead guilty to two counts of conspiracy to commit arson and tell the court about other conspirators and two failed attempts to blow up her house.

“We knew that after last week’s plea agreement with Moncy and everything that it was probably going to happen sooner than later”,” said Doug Aldridge, a Richmond Hill resident.

The arrest is also helping the people of the south side resident impacted by the blast inch towards closure.

“This is what it’s all been about. This is justice for the Longworth’s. It’s justice for the people that lost their homes here,” said Aldridge.

Shirley told police Thompson is one of the others, and investigators think he participated in an earlier attempt to destroy the single mother’s home for an insurance payoff.

After last week’s plea agreement hearing, lead deputy prosecutor Denise Robinson said she looked forward to debriefing Shirley.

“Thus far, the information she’s provided has been consistent with what we know about the investigation. We’ll continue to corroborate it,” said Robinson. “If at any point any information she gives us is not truthful, then we certainly have no interest in moving forward with her testimony and we would not move forward with the plea.”

PHOTOS: Richmond Hill explosion