BOSTON — With the identification of “Baby Doe” as 2-year-old Bella Bond, Gov. Charlie Baker finds himself again thrust into the sad – and sadly familiar – position of responding to the death or mistreatment of a child at one point under the supervision of the state.

Last month, a 2-year-old girl in foster care died after being found unresponsive at an apartment complex in Auburn. Earlier this summer it was the case of Jack Loiselle, a 7-year-old Hardwick boy who police say was beaten and starved by his father before falling into a coma. A report found the Department of Children and Families failed to pull together multiple abuse reports to adequately protect the boy.

Then came the identification of Bella as the toddler whose body was found on a Boston-area beach in June. DCF said the agency had been involved with the girl twice when she was an infant in 2012 and 2013. The cases were then closed.

Her mother, Rachelle Bond, 40, is charged with being an accessory after the fact to Bella’s death. Bond’s boyfriend, Michael McCarthy, 35, is charged with murder for allegedly punching the girl in the abdomen until she stopped breathing.

All three echo the 2013 case of Jeremiah Oliver, a 5-year-old Fitchburg boy whose remains were found alongside a highway after social workers lost track of him.

The cases pose a unique challenge for Baker – a self-described policy wonk – who served as secretary of health and human services under then-Gov. William Weld in the 1990s.

As a candidate for governor last year, Baker cited the Oliver case in calling for the resignation of then-DCF Commissioner Olga Roche, appointed by former Gov. Deval Patrick. Patrick initially resisted demands for Roche’s resignation, saying he wanted to focus instead on overhauling the agency, but eventually relented.

As governor, Baker also says he wants to focus on systemic problems in the agency.

“The problem here is the policy. The easy thing to do would be to fire somebody over that,” Baker told reporters after the release of the report criticizing DCF’s handling of 7-year-old Jack. “The hard thing to do is to fix the policy and then to hold people accountable.”

Baker says a key to addressing the agency’s troubles is revamping the way it handles investigations into allegations of abuse or neglect of children.

“One of the great problems we have here … is inconsistent or misunderstood application of whatever the rules or the practice standards that exist,” Baker said this week. “In many cases they don’t exist at all.”