An unemployed Grantville man pleaded not guilty today to murder and assault charges in the death of his 2-year-old son.

Bennie Harris Jr., 28, who has a 2006 robbery conviction on his record, faces 55 years to life in state prison if convicted, Deputy District Attorney Harrison Kennedy said outside court.

"It's hard to deal with," the prosecutor said, referring to the death of a child.

He declined to comment on the case further because it wasn't discussed in open court.

Judge David Szumowski ordered Harris held on $1 million bail and scheduled a status conference for March 5.

The defendant was arrested Tuesday at an El Cajon residence that police said might belong to a relative.

About 7:30 p.m. last Thursday, Harris made an emergency call from his home in the 10200 block of San Diego Mission Road to report that his son, Bennie Harris III, was unconscious and had stopped breathing.

The boy was pronounced dead the next afternoon at Rady Children's Hospital. An autopsy determined that the toddler had succumbed to blunt-force head trauma.

Harris and his son lived in the residence near Qualcomm Stadium with the boy's mother, but the father was the only person with the child when he suffered the fatal injuries, according to San Diego police Lt. Kevin Rooney.