Baby Doe identified as Bella
Rachel Bond stopped posting photos and videos of the toddler on Facebook after December 2014Facebook

Police have charged the mother and live-in boyfriend of the girl found dead in a plastic bag on a Boston beach. District attorney Prosecutor Daniel Conley told a press conference the boyfriend, Michael McCarthy, 35, was charged with murder. The mother, Rachelle Bond, 40, was being charged with being an accessory after the fact, Mr Conley added. The two were arrested on Friday (18 September).

Earlier police confirmed they had identified the toddler as Bella. The child, who is believed to be four-years-old, was found washed up on the Boston Harbour shoreline three months ago. The grim discovery was made by a woman walking her dog on Deer Island, on June 25.

Her mother, Rachelle Bond, 40, and Michael McCarthy, 35, were described as persons of interest.

Baby Doe identified as Bella
Bella's mother Rachel Bond has been charged as an accessory in her murderAFP/Getty

The three-month-long search to determine the identity of the child named Baby Doe by investigators, ended on Thursday (18 September), when someone close to the child's family contacted police. They had noticed the child was missing, but each time the person asked Bella's parents what happened to her, they replied that she had been taken away by the Department of Children and Families.

The Department of Children and Families told the Boston Herald it investigated the mother's treatment of Bella twice before, in 2012 and 2013. The Boston Globe reports that state officials had previously removed two other children from the mother's care.

"DCF has not had an open case with this family for over two years, but did have brief involvement with Baby Bella as an infant," spokeswoman Rhonda Mann told the Herald. "Our thoughts are with Bella's extended family as the investigation into her death continues."

A computer-generated image of Bella was created by the National Centre for Missing and Exploited Children and posted on billboards across the state, in the hope it would generate clues about her identity.

Investigators were finally able to trace the girl to Boston by examining pollen gathered from her clothes. The girl had brown hair and brown eyes and was wearing white leggings with black polka dots. The victim's body showed "no obvious signs of trauma" and the state medical examiner's office could not determine the manner or cause of death after an autopsy was performed.

An official told AP news agency that police have searched a Boston home in the city's Mattapan district on Thursday (17 September) and have been in contact with family members including an unidentified woman.

Baby Doe identified as Bella
Police said Bella's mother attempted to portray herself on social media as a caring motherFacebook

According to Sky News, neighbours who were questioned about the child said the woman had a young daughter who they had not seen since the summer. Siomy Torres, who lives next door, told the Boston Globe there were "always guys in and out of the house. Half the time she was crying."

Another neighbour, Yessiomora Torres, told WCVB: "She (the mother) tried to be responsible, but she was on drugs. "She talked slurred, she'd come out and smoke a cigarette, her daughter would be crying."

Massachusetts House Speaker Robert DeLeo, whose district covers the area where Bella was found, said it was a "sad day".