A 2-year-old boy was beaten to death for allegedly wetting his pants and his mother's boyfriend has been charged with his murder, Conyers police said.

Cayden Allen died Monday at Children's Healthcare of Atlanta at Egleston, where he was being treated for brain hemorrhages, according to Jennifer Edwards, spokeswoman for Conyers police.

Police were called Friday night to a Main Street apartment, where they found the toddler unconscious and struggling to breathe, Edwards said. Cayden's mother was at work and the child was in the care of his mother's boyfriend, 23-year-old James Rivera Sims.

The boy had apparently wet his pants and Sims told police he grabbed the boy and took him into the restroom, Lt. Jackie Dunn with Conyers police told the AJC.

"He said he grabbed him by the arm and he just collapsed," Dunn said.

Because his account of what happened was inconsistent with the boy's injuries, Sims was arrested Friday night and charged with first degree cruelty to children, police said.

An autopsy completed Wednesday determined Cayden's head had been struck several times, Edwards said. Also, both of the boy's testes were swollen and bruised, she said.

"These were not blows that he would survive for a period of time," Dunn said.

Sims now faces a murder charge in the death of the child.

Cayden had been in his mother's custody for two weeks at the time of his death, Dunn said. Previously, the boy had been in the custody of grandparents.