INDIANAPOLIS -- The woman at the center of the Richmond Hill Explosion, Monserrate Shirley, received a sentence of 50 years in prison Tuesday for her role in the deadly 2012 blast.

The sentence was handed down by Judge Sheila Carlisle following two days of evidence and testimony, including statements from neighbors and family members of Dion and Jennifer Longworth – the couple killed in the blast.

The sentencing hearing was the first opportunity Shirley's neighbors have had to speak directly to her about the explosion since her arrest in December 2012. It was also an opportunity to weigh in on what they thought the appropriate sentence was. All who asked for a specific sentence said they thought Shirley deserved the maximum allowed by law.

"I don't think she should ever get out of prison," said Brookley Longworth, the sister of Dion Longworth. "I don't think she should ever hold her daughter again."

Unlike the two other primary co-conspirators in the case – Shirley's former boyfriend Mark Ray Leonard and his brother, Bob Leonard Jr. – Shirley avoided the possibility of life without parole thanks to a plea deal reached in January 2015.

In that deal, Shirley agreed to testify against her co-conspirators and to provide information about the insurance fraud scheme. Investigators say the plan was to destroy Shirley's home in the Richmond Hill neighborhood in order to collect a $300,000 insurance policy.

In exchange, prosecutors allowed Shirley to plead guilty to just two charges of conspiracy to commit arson. She faced a sentencing range from a suspended 20-year sentence to 50 years behind bars.

In her closing arguments, Deputy Prosecutor Denise Robinson pointed to a statement Shirley made to an IMPD detective following the blast. In that statement, Shirley said she thought whoever was behind the explosion should spend the rest of their life behind bars.

"She knew it to be the fair sentence," Robinson said. "But she's not going to spend the rest of her life in prison, because she did accept responsibility and she did cooperate with the prosecution."

SPECIAL SECTION | Richmond Hill Explosion

Shirley's defense team called mental health experts to testify on her behalf, saying she'd had a troubled childhood with an alcoholic and abusive father. One expert, psychologist Dr. Stephanie Callaway, said she had diagnosed Shirley with depression and dependent personality disorder.

"She saw how her mother would try to please and placate her father in order to avoid the violence," Callaway said. "As she grew up, those were the things that carried forward and caused significant problems for her and her relationships."

Robinson said she didn't doubt Shirley had a troubled childhood, but that it didn't excuse her actions or absolve her of guilt.

"That house, that insurance policy, those vehicles were all in her name," Robinson said. "That money – Mark Leonard may have had his designs on it – it all flowed through her."

MORE | Read Monserrate Shirley's full sentencing statement

Shirley's attorneys, Jim Voyles and Jennifer Lukemeyer, also said they didn't think her upbringing excused her actions. But, they said, it should mitigate her punishment.

"We reserve the maximum sentence for the worst offenses," Lukemeyer said. "And this is one of the worst offenses. But it's not one of the worst offenders."

Judge Carlisle ultimately came to a different conclusion. Before reading her sentence, Carlisle said she kept coming back to two words: "but for."

"But for Monserrate Shirley, none of this would have happened," Carlisle said. "But for you letting Mark Leonard into your home. But for you increasing that insurance policy. But for you arranging the alibi. But for you taking care of your daughter and your cat. You obviously knew the dangers of that plan, otherwise you wouldn't have sent Brook away. You took care of your loved one, your cat and some treasures from your home, but you didn't take care of your neighbors."

Carlisle described the case as the worst arson in Indianapolis history, and said she had never seen a case in 30 years with a crime that impacted so many people.

"You were a mom. You were a nurse. You were a neighbor, and you were a friend," Carlisle said. "And in each of those categories, you betrayed your trust."

Shirley will receive 461 days credit for time served as well as 461 days in "good time." If she serves her time without incident, she could be released from prison after serving 21 years of her sentence -- in 2032 at the age of 72.