And it's lead to charges against the baby's mother and her boyfriend.
Police arrested 45 year old Juan Duran on felony charges of child abuse, attempted murder and sex abuse.
The baby's mother Jade Olsen was charged with one count of child abuse.
It happened two weeks ago at an apartment in Midvale.
Police came to the home after the baby's mother called police.
""He (Duran) was seen trying to smother the child and had made statements that this child was dead," says Salt Lake District Attorney Sim Gill.
The baby's mother also told police he threatened to toss the six month old out of the window.
Duran was arrested. But he's now accused of beating, squeezing and shaking the baby.
According to court records "the baby had five discreet bruises apparently from inflicted blows to his head."
The doctors who treated the six month old baby also reported that "older bruises" and "there were multiple inflicted bite marks along with another bite mark around his left nipple."
Dr. Lori Frasier with the Safe and Healthy Families team at Primary Children's Medical Center noted that the baby "had bruises on his scrotum and on the skin near his penis."
She concluded that "the pattern of external marks and bruises were likely all inflicted injuries from blunt force trauma, squeezing, biting and/or pinching his skin in an abusive manner.
She wrote "the baby appeared to be depressed and looked sad ... a sign of a battered infant.
doctors say the baby "could easily have been killed and was at extreme risk of death or disability."
"There were fractures in terms of ribs and the humerus as well as
liquid in the brain," says Gill.
The baby's mother, Jade Olsen was also charged with child abuse.
Prosecutors claim she knew about the beatings but looked the other way.
"She admitted that she was aware of the abuse that was being inflicted on this six month old infant but did not report it to anyone," Gill says.
He says Olsen told police she was afraid to report the abuse. Now both mother and boyfriend are facing felony charges.
Gill says the child is with social services but is not sure of the baby's long term physical health.