SAN DIEGO -- A Paradise Hills man accused of killing his 3-year-old stepdaughter by repeatedly punching her in the stomach last weekend pleaded not guilty Thursday to murder and assault charges.

Christopher Lovell Simmons, 24, was ordered held on $5 million bail.

Deputy District Attorney Lindsey Krause told Judge Frederick Maguire that Simmons, a Navy chef stationed aboard the USS Kidd, was in his stepdaughter's bedroom in the early afternoon last Sunday when the child's mother heard some thumping on the wall and went to investigate.

When the mother got into the bedroom, she saw Simmons punching Armani Hansberry in the stomach, the prosecutor alleged.

The toddler's health deteriorated over the next four to five hours until she fell unconscious, and paramedics were called to the Pacific Mist Road home about 5 p.m., Krause told the judge. The child died about 45 minutes later at a hospital, the prosecutor said.

A deputy medical examiner said the child died from blunt force trauma to the abdomen due to a lacerated liver, according to the prosecutor.

The defendant -- whose family lives in Michigan -- faces 25 years to life in convicted, Krause said.

Maguire scheduled a status conference for May 8 and a preliminary hearing for May 14.