PHILADELPHIA -- Prosecutors plan to file homicide charges against a couple accused of starving an 18-year-old boy, then putting the dying teen on a bus and sending him to find his estranged father in Florida, a defense attorney said.

Paul Hoffman and Lyda Miller of Hazleton have been jailed on assault charges since September, when Miller's emaciated son, Chester, knocked on a stranger's door in Milton, Fla., after a two-day bus trip and begged for help.

The teen was delirious and weighed less than 65 pounds when he was admitted to a Florida hospital. He died four days later.

According to prosecutors, Chester said before he died that he had been beaten and starved for months by his mother and Hoffman, her live-in boyfriend. A medical examiner in Florida this past week declared the death a homicide, clearing the way for the criminal charge.

Hoffman and Miller have both denied starving the boy. They have said the teen was taking Adderall, an amphetamine prescribed for attention deficit disorder that can cause a loss of appetite.

The two are charged with assault and reckless endangerment, but Hoffman's attorney, John Pike, said Friday that prosecutors planned to file homicide charges. A general homicide charge allows jurors a choice of five verdicts, ranging in seriousness from first-degree murder to involuntary manslaughter, a misdemeanor.

By Monday, Hoffman and Miller would have been in jail for 180 days, and under state speedy-trial laws would be entitled to release on "nominal" bail, unless more serious charges are filed, Pike said.

"They don't want to release them," Pike said. Bail had been set at $500,000 for Miller and $100,000 for Hoffman.

Investigators said Chester Miller lived with the couple for about a year after moving out of his father's home in Florida. Starting in May, they claim, Hoffman refused to let the teen eat because he was upset at having him in the house.

In a phone interview from prison, Hoffman has acknowledged that he occasionally hit Chester to discipline him, but said the teen was always offered food and had a summer job.

In a separate jail interview, Lyda Miller has said Hoffman was abusive and frequently prevented her son from eating meals. She said she was unaware Chester was malnourished.

Miller's attorney, Lewis Bott, did not immediately return a phone call.

Pike said murder charges against the couple would be inappropriate.

"I don't think first-degree murder applies at all. That would constitute some sort of prior intent to cause death, and I don't believe that was the case," he said.