Upper Darby police have launched a nationwide search for the man they believe beat his 3-month-old boy so severely that the child may have suffered permanent brain damage.

Henry Paris III, 32, of Taylor Avenue near Burmont Road in Drexel Hill, was charged yesterday with aggravated assault and related charges that could carry a prison sentence on par with third-degree murder because of the victim's age, police Superintendent Michael Chitwood Sr. said.

"Right now, there's no doubt that this bum is responsible for this child's injuries," Chitwood said.

The infant, Henry Paris IV, has been upgraded from critical to stable condition at Children's Hospital of Philadelphia, where he is being treated for a skull fracture, cerebral hemorrhaging and broken ribs. The injuries were reported to police on Nov. 24 by the child's babysitter, who has been cooperating in the investigation.

"We see a lot of people who are victims in our society, and the most difficult victim, in my opinion, is a small child," Chitwood said, adding that the baby might never fully recover.

"Due to the significance of the injuries and the number of issues that this small child will have to overcome during his lifetime, we suspect that he will be dependent on others for the rest of his life," he said.

Chitwood said Paris fled the area late Thursday night or early yesterday morning.

According to the criminal complaint filed yesterday, Paris told a friend in New York that he dropped the baby while intoxicated. But a doctor at Children's Hospital told police that the injuries were not consistent with a "short-distance fall."

Two of Paris' former co-workers told investigators that he has a short fuse and quickly loses his cool, according to the court document. The infant's mother said he is prone to overreact and has "raised his hand to her on past occasions," police said.

Paris is believed to be driving a white Nissan car with the Pennsylvania license plate GWK-2718. Anyone with information on his whereabouts should call Upper Darby detectives at 610-734- 7677.

Meanwhile, another Delaware County father is charged in a similar case of abuse that allegedly occurred just days earlier. Police say Reginald Dennis, 31, of Chester, is responsible for fracturing the skull and ribs of his 2-month-old boy, Brady, who remained hospitalized yesterday. Dennis is awaiting his preliminary hearing next month. *