A mother, who had mercilessly killed her 5-month-old son by repeatedly slamming his head into the apartment wall, was sentenced to 10 years in prison.

A somber and puffy-faced Joann McLeod, 31, stood mutely in a white sweater and slacks as the jail term was imposed on her guilty plea to manslaughter for fatally beating helpless little Raymond Porfil Jr.

The killer mom kept her head down throughout the brief Bronx Supreme Court sentencing, turning her face away when courtroom photographers tried to snap her picture. McLeod, described by relatives of the boy’s father as a drug-addled woman with a taste for synthetic marijuana, let her hair fall down over her eyes for most of the hearing before she was led away.

“The defendant inflicted grievous head injuries on the infant and left him to suffer for more than an hour before obtaining medical attention,” said Bronx District Attorney Darcel Clark in a statement. “She will now serve time in prison for callously causing the death of this innocent child whose life had barely begun.”

Defense lawyer Suzanne McElwreath declined to comment after Judge James McCarty delivered the predetermined sentence. The tiny victim died of a cracked skull and brain injuries after his mother repeatedly bashed his head against the wall inside their Bronx River Houses apartment in Soundview on June 4, 2018.

McLeod pleaded guilty on Oct. 22 to first-degree manslaughter for the heinous killing. In a deal with prosecutors, she will serve 10 years in state prison with five years of post-release supervision.

In an exclusive interview with the Daily News in June 2018, McLeod denied beating little Raymond to death.

“I don’t know what happened,” she claimed. “I don’t know what happened because the autopsy didn’t say.”

But court documents indicated that McLeod, during an interview with a city Administration for Children’s Services, acknowledged that she repeatedly slammed the baby’s head against a wall.

The suspect further confessed that she failed to get the dying child medical attention for more than an hour, even leaving the apartment when her mortally injured son’s body went limp because she was “afraid of going to jail,” according to court documents.

Eight years prior to Raymond’s killing, ACS removed three of McLeod’s children — who were between 1 and 5 at the time — due to her neglect and drug use around the kids, according to officials. She was accused of physically assaulting her children before Raymond’s death.