Even before they heard that family photographs were missing, investigators said they sensed something was not right with the scattered remains of Monserrate Shirley's home.
An explosion inside her house devastated an Indianapolis neighborhood on Nov. 10, killing two neighbors, injuring 12 and damaging more than 30 homes beyond repair. Left behind were mounds of debris and questions about what caused the blast that would take investigators weeks to sort through -- from suspicions of foul play to the nuances of microwave ovens.
"Virtually on Day 1, I think it's fair to say we knew an intentional act was involved," said Terry Curry, the Marion County prosecutor who brought murder and arson charges against Ms. Shirley and two others on Dec. 21. Authorities say there is a continuing investigation of a fourth, unidentified suspect.
Nearly two months and 20 search warrants after the explosion, a multiagency effort of scientific and shoe-leather police work has unearthed an account of what investigators believe caused the blast and details of a suspected scheme to collect insurance money that went horribly, and fatally, wrong.
Officials believe the home, in the Richmond Hill subdivision, had been saturated with natural gas for six to nine hours before it erupted at 11:11 p.m. The explosion was seen and felt for miles. It shattered windows and collapsed walls throughout the neighborhood, shoving some homes off their foundations. John D. Longworth and his wife, Jennifer, who lived in the house next door, did not survive.
"There were homes that were two blocks away that faced the other direction and their garage doors were buckled by the force of the blast," said Troy Riggs, director of public safety for Indianapolis. Around 200 police officers and firefighters secured and evacuated the neighborhood that night, he said. In all, the explosion caused an estimated $4.4 million in damage to the subdivision.
Ms. Shirley, 47, and Mark Leonard, 43, her boyfriend, were 100 miles away at a casino when their home blew up. They had left town the night before, after Ms. Shirley's nursing shift at a local hospital, leaving her 12-year-old daughter at a friend's house for the weekend. Their Persian cat, Snowball, was boarded at a grooming business.
Returning to a blitz of media attention, Ms. Shirley told the police and reporters that she was surprised and devastated by the blast. She said that furnace problems had forced the couple to spend the night at a hotel the previous weekend and that her daughter had smelled a gas-like odor in their garage and laundry room.
But according to a probable-cause affidavit filed in court by prosecutors last month, doubts surfaced when local and federal explosives experts began sifting through the wreckage of Ms. Shirley's kitchen, where the blast appeared to have originated.
Instead of being crushed, the microwave oven had blown apart from the inside out, investigators reported. A timer, they theorized, could have been set to turn the microwave on hours after everyone had left, sparking the gas explosion.
After shoveling through the debris, investigators also said they were unable to find a crucial gas valve and another regulator part that would have limited the flow of gas from Ms. Shirley's fireplace, suggesting both may have been removed. Testing of gas mains throughout the neighborhood indicated no sign of accidental leaks.
Within two weeks, officials believed they had enough evidence to announce that a homicide investigation was under way. By then, public suspicion had risen about the involvement of Ms. Shirley and Mr. Leonard.
"It's like waking up to this bad dream," Ms. Shirley said, crying as she spoke to The Indianapolis Star in November. "I mean, sometimes I wish I was there and I'd be dead and now I wouldn't have to be asked so many questions."
An examination of Ms. Shirley's background revealed a history of troubled finances and, for the police, a possible motive. In 2007, she and her husband filed for bankruptcy. Divorce documents showed that Ms. Shirley took control of two mortgages -- now totaling more than $200,000 -- and the bankruptcy payments after the couple split last year. She currently owes an additional $63,000 in credit card debt, investigators learned.
Randall L. Cable, a lawyer for Ms. Shirley, did not respond to requests for comment, but in an interview before Ms. Shirley and Mr. Leonard were arrested on Dec. 21 he said that they were "as bewildered as everyone else" about the explosion. "It's always neater if they can blame somebody," Mr. Cable said, about police and news reporters, denying his client's involvement.
Court documents show that circumstantial evidence against the couple continued to mount, including a $304,000 homeowners' policy on Ms. Shirley's personal property; an account of a conversation between Mr. Leonard and a friend suggesting a failed attempt to detonate the house a week before the explosion; and evidence that a large plastic tote containing Ms. Shirley's family photographs and other personal items was given to Mr. Leonard's nephew for storage.
Ms. Shirley, Mr. Leonard and his brother, Bob Leonard -- who is suspected of entering the house on the afternoon of the explosion with another person -- were arrested and jailed without bond. They each face two counts of felony murder, 45 counts of arson, and charges of conspiracy to commit arson. A lawyer for Bob Leonard, Ted Minch, said his client denied the allegations and expressed concern about Mr. Leonard getting a fair trial after the national attention the case has received. Mark Leonard's lawyer declined to comment.
Last week, just days after the three defendants made their first appearance in court, workers began demolishing what little was left of the Richmond Hill residence where the Longworths were killed.
Next door, authorities have kept Ms. Shirley's property secured as a crime scene. Behind a fence, the wreckage sits undisturbed by cleanup crews that have so far razed at least 21 houses in the neighborhood -- a sign that more questions may linger.
This article originally appeared in The New York Times.