Matthew Albert Worthen was charged on Monday, with one count of murder and with one count of assault on a child causing death, for the fatal beating of Zanai, according to the District Attorney's Office in Los Angeles.
The fatal beating occurred on Sunday September, 22, in the couple's apartment in the 200 block of Avenue R, according to detectives.
The boy's mother told detectives that she left Zanai Noel alone with Worthen for a few minutes while she went to the store.
"She came back six to seven minutes later and her baby was having difficulty breathing as if in shock," police said.
Zanai was near death when Worthen and the girl's mother brought her to Palmdale Regional Medical Center around 9:25 p.m.
"She had severe internal injuries consistent with heavy blows to the back causing rib fractures, bleeding, collapsed lung, internal bleeding and liver damage," medical staff said.
Zanai died an hour after arriving at the hospital.
Worthen was arrested on Thursday, after a forensic autopsy confirmed the cause of death.
The child's mother has not been arrested or charged in the incident so far. Zanai's biological father, Robert Skinner, said the mother and her boyfriend are responsible for the death of his daughter.
"I want them both buried in jail," Skinner said.
Worthen was arrested for a domestic violence incident in July 2013, and his girlfriend had filed a restraining order against him.
"There was a restraining order, however, we believe that the order expired and we are studying it," police said.
If convicted of the charges, Worthen faces a maximum sentence of life imprisonment.
What could this innocent child have done to warrant been beaten to death by anyone? My heart bleeds. May her soul rest in peace, Amen.
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