A Brooklyn mother and her boyfriend were held without bail Sunday after being arraigned on second-degree murder charges in the beating death of the woman's four-year-old son.

Police arrested Myrna Chenphang, 25, and her live-in boyfriend, Steven Dadaille, 26, on Saturday after the medical examiner declared Jayden Lenescar's death a homicide.

Published reports say the Crown Heights couple gave written and taped statements blaming and implicating each other for the boy's death.

Both are due back in court next week.

"They will be assigned a lawyer, both of them, on Friday," said court-appointed attorney Jesse Young. "It's standard. We don't necessarily say 'not guilty' but it's understood it's 'not guilty.'"

The medical examiner said Lenescar, seen right, died of blunt impact injuries to the torso, arms, and legs.

"I still think it's terrible and they should charge them because it's murder," said one local.

"It's just sad. These little kids are innocent, they depend on their mother and father to take care of them," said another local. "And for something like that to happen, I just, I don't know what to say."

Neighbors told NY1 that they never suspected the charged couple of wrongdoing.

"[Chenphang] couldn't. She's too much of a nice person to do something like that," said a neighbor. "The way she held him, the way she was around him, protected him, nothing struck me as wrong, which is why it's so hard to believe it's an accident."

"I've lived here 25 years, and they're good people. They're good people," said another neighbor.

Police say officers responded to a call of an unconscious child at a home in Crown Heights Friday night and found Lenescar unresponsive.

He was later pronounced dead at Kings County Hospital.