OSWEGO - A 29-year-old man must serve at least 25 years in prison for strangling his 11-year-old stepsister - whose life authorities said was beset by starvation, isolation and squalor - a judge ruled on Monday.

Alan Jones was sentenced to the maximum penalty after Oswego County Judge Walter Hafner Jr. rejected a defense motion to set aside Jones' conviction for killing Erin Maxwell at the family's home in Palermo.

Before he was sentenced, Jones told Hafner he was confident the verdict would be overturned on appeal. Defense attorney Salvatore Lanza said he would file an appeal Monday.

Jones was convicted of second-degree murder in September; his sentence ranges from 25 years to life.

Lanza argued during the trial that Erin accidentally hanged herself while acting out a scene from the “Pirates of the Caribbean” movies in her bedroom on Aug. 29, 2008. Prosecutors said Jones strangled the girl, but they have never offered a motive.

State police and rescue workers said they found more than 100 cats in the Maxwells' home at the time of Erin's death. Troopers also found the carcasses of several kittens in the freezer.

Authorities said Erin was routinely locked in her room at night and spent hours alone. She had no playmates and often went to school in clothes reeking of cat urine.

Teachers and other school officials told investigators that she had been seen taking food from garbage cans and eating it or putting it in her desk.

The parents, Lynn and Lindsey Maxwell, were convicted of multiple child endangerment charges and were each sentenced to two years in jail. The Maxwells, also represented by Lanza, have appealed.

Jones is biological son of Lynn Maxwell and Lindsey Maxwell's stepson; Erin Maxwell is Lindsey Maxwell's biological daughter and Lynn Maxwell's stepdaughter.

Lindsey Maxwell was brought to court from jail Monday to ask for a reduced sentence for his stepson.

“I don't think I really have to tell you how my family feels about this case,” Lindsey Maxwell said.

“Erin and Alan were best friends. He was her greatest defender,” Maxwell said. “I don't think my daughter would want Alan to lose any more of his life ... to suffer for something on her account.

“We have already lost our daughter. We don't want to lose our son.”

Lanza raised three issues in asking Hafner to set aside the verdict.

The defense attorney claimed the jury deliberations may have been tainted, noting that a juror came forward after the trial and said he thought Jones might be innocent and had raised questions about improper discussions in the jury room.