A 2-year-old Alaska boy has been killed by guardians months after his mother’s death at the hands of her husband, authorities said.

Steven Melovidov and Sophie Myers-Melovidov killed the boy in their home on a remote Alaska island and attempted to mislead investigators, authorities said. They were charged with first-degree and second-degree murder and fourth-degree assault and will be arraigned Thursday, according to court records.

Earlier this month, the toddler, Joshua Rukovishnikoff, was medevaced from St. Paul Island to Anchorage with a serious head injury, according to state troopers.

The boy died at an Anchorage hospital and an autopsy was conducted.

“Both of the suspects made statements to investigators that proved to be false after further investigation,” said Alaska State Troopers spokesperson Austin McDaniel.

They were being held without bail and it wasn’t immediately clear if they had attorneys.

The child’s mother, Nadesda Rukovishnikoff, was killed in September on St. Paul Island and the couple became his guardians in October, McDaniel said.

McDaniel said he didn’t have details about the custody arrangements.

The mother’s husband, Joshua Rukovishnikoff, was indicted in her death, KTUU reported.

He has pleaded not guilty to murder and other charges, according to court records. The Alaska Public Defender Agency, which represents him, declined to comment on his case Thursday.