Three year-old Alonzo Soeuk's death was ruled suspicious a month ago and now Columbus Police believe he was murdered.
His mother's live-in boyfriend, Roberto Avina-Casillas, is now charged with the crime.
A warrant has been issued for his arrest.
Souannarath Sem said the child, his mother and Avina-Casillas had only been living with her in her south side home on Buffalo Court for a week.
She said she remembers clearly the bruising on the Soeuk's face and the unusual behavior he exhibited moments before he died on August 7.
"He was sick looking that's how he looked. he was pale," said Sem.
She said she has no idea what happened to Alonzo that night but believes Avina-Casillas is to blame.
Columbus Police need the public's help in locating Avina-Casillas.
Anyone with information is asked to call (614) 645-4545, or Crimestoppers at (614) 645-8477.