BOSTON -- The man accused of killing 2-year-old Bella Bond, the cherubic girl whose unidentified remains were found in a trash bag two years ago near Boston, was obsessed with the occult and thought the young girl was a demon, Suffolk County prosecutors said in opening statements on Tuesday.
Michael McCarthy, the then-boyfriend of the girl's mother Rachelle Bond, has been charged with first-degree murder for allegedly killing Bella, either by suffocating her or punching her in the stomach repeatedly. Her body was stored in a refrigerator and then put in a plastic bag and dumped into the water, authorities said.
McCarthy has pleaded not guilty to murder. His defense attorney alleged that Rachelle Bond was the one truly obsessed with demons and that she was "probably" Bella's true killer.
"He had nothing to do with her tragic death. Michael did not even know that Bella was dead until the police who arrested him told him," McCarthy's defense attorney Jonathan Shapiro said. "The prosecution's case rests entirely upon the uncorroborated and unbelievable testimony from Rachelle Bond."
Bond was charged with accessory after the fact for allegedly helping to dispose the child's body, and she pleaded guilty in February.
Both Bond and McCarthy have struggled with heroin addiction, authorities said. Bond will testify in the case as part of a cooperation agreement with prosecutors, and she will be sentenced to probation as part of the agreement.
Bella Bond's case dates to June 2015, when a woman walking her dog discovered the gruesome bag with a young girl's partially decomposed remains off the shoreline of Deer Island in Boston. A zebra-print blanket and polka dot leggings were also found in the bag, located just east of Boston's Logan International Airport.
Authorities launched extensive efforts to identify the girl known as "Baby Doe," and an artist's image of the doe-eyed girl was shared widely. Tips poured in to investigators as to her identity, but the killing remained a mystery for months.
The investigation broke open in September when Bond admitted to a friend that her daughter Bella was dead, and that the girl had not been taken away by the state's Department of Children and Families as she had previously claimed.
The friend, Michael Sprinsky, looked up the story of "Baby Doe" and recognized the blanket and leggings as Bella's. He then came forward to authorities with what Bond said, leading to the arrests.
According to prosecutors, Bond said she saw McCarthy strike Bella one night and that the girl's face turned blue and lifeless.
"She just died. It was her time. She was a demon," McCarthy said, according to prosecutors.
McCarthy allegedly threatened Bond not to tell anyone, and then the two binged on heroin and other drugs, prosecutors said. The two then allegedly put her body in a bag with weights and dropped the body into the water.
Prosecutors said Bond did not report the incident to police because she was afraid of McCarthy. Bond was "trapped" by his abusive behavior and by her own drug use, prosecutors said.
Defense attorney Shapiro said McCarthy was not obsessed with the occult and Satanism, and said that he was a good father who cared for Bella.
Instead, Rachelle Bond was the one obsessed with the occult, Shapiro said.
"At the end of this trial you will realize that Rachelle was projecting her own delusions onto Michael, and that she blamed him for what she in fact did," Shapiro said.
He quoted Bond's diary entry from the summer of 2015, in which she wondered why so many children who go missing are never found.
"That's because the leaders of every country get together and torture and rape and kill these innocent children every year just so they can drink their blood and eat their flesh, so that these reptilian demons can have a moment's sanity," Bond wrote, according to Shapiro.
Copyright 2017 Cable News Network. Turner Broadcasting System, Inc. All Rights Reserved.