MAYS LANDING — An Atlantic City man who allegedly told investigators he lost his cool when he fatally shook a baby in his care pleaded not guilty Tuesday.

Daquan Davis, 19, was indicted last month or charges of aggravated manslaughter, manslaughter and endangering the welfare of a child in the Sept. 14 killing of 6-month-old Yusuf E'Miy Stewart-Ali Jr.

Davis -- who was not the baby's father -- was caring for the boy at the mother's Schoolhouse apartment in Atlantic City, where all three were living at the time.

Ebony Stewart found her son unresponsive when she returned home from work at about 3:45 that morning, and called 911. Yusuf was pronounced dead, with the cause of death later ruled an acute cerebral spinal trauma.

Davis' attorney said the arraignment "is just the first step in a long process of vigorously defending Mr. Davis."

"We are in the process of reviewing the police reports, witness statements and medical evidence," attorney Joseph Levin said.

The man admitted to losing his cool with the baby, according to parts of a statement he gave to investigators previously quoted in court.

Davis has also submitted to DNA evidence in an attempt by the prosecution to link him to marijuana stubs found at the scene.

He is being held in jail on $500,000 cash bail.