Man admits to shaking infant nephew, police say

A murder defendant admitted he shook his infant nephew when the boy began to cry, police say.

Isaiah Dontae Cosby, 22, of Oklahoma City, was initially charged with child abuse, accused of injuring 4-month-old Darren Cosby Jr. between late March 31 and early April 1 while babysitting for the boy’s parents.

On Friday, Oklahoma County prosecutors amended the charge to first-degree murder because the boy died June 7 at a Bethany hospital.

The state medical examiner reported cause of death as a traumatic brain injury.

About 3:30 a.m. April 1, the boy’s father woke up to check on his son and discovered the child wasn’t breathing, police reported in a court affidavit.

Paramedics were then called to the north Oklahoma City apartment to take the baby to a hospital.

Darren suffered brain bleeding, skull fractures, head swelling and eye injuries, police said. Doctors determined the injuries were the result of “non-accidental trauma.”

Isaiah Cosby later told police he was the sole caretaker for the child the night before the boy was found unresponsive, police reported.

The boy woke up

Cosby said he had hoped (the baby) would recover from the shaking but it was obvious now that he was not recovering.”

and began to cry while Cosby was baby-sitting, police reported. Cosby said he went to the boy’s bedroom to quiet the child, according to the affidavit.

Cosby said he picked up the child and began to shake him, police reported.

He said the boy’s head was “rolling from side to side,” and he quit crying, according to the affidavit.

Cosby said he then struck the baby’s head on a metal corner of his bed while putting him back down, police reported.

He told police he knew the baby was injured but he didn’t call for help “because he was scared of getting in trouble,” according to the affidavit.

“Cosby said he had hoped (the baby) would recover from the shaking but it was obvious now that he was not recovering,” a police investigator reported.

When Cosby confessed, he said, “he needed to get it off his chest,” police reported.

Cosby also told police “he was not good with kids,” according to the affidavit.

He has been in jail since April 5. He currently is held without bail.