BOSTON -- A Dorchester foster mother convicted of manslaughter in the death of a 4-year-old boy in her care has been sentenced to eight to 12 years in prison -- more than twice the sentence length recommended by state guidelines.

Corrine Stephen, 26, was convicted of involuntary manslaughter in the death of Dontel Jeffers in March 2005. Officials said that the boy was beaten in the stomach so hard that his organs were perforated, which led to a fatal infection.

Jeffers died 10 days after he moved in with Stephen. The Massachusetts Department of Social Services placed Dontel with the Dorchester woman.

Stephen, the mother of a 5-year-old, was charged with second-degree murder, which carried a mandatory sentence of life in prison, but the jury found her guilty of a lesser charge.

Acknowledging that state guidelines suggest sentences ranging from probation up to 40 to 60 months in prison, Suffolk Superior Court Judge Margaret H. Hinkle said "the circumstances of this case do mandate departure from those guidelines" because, in part, Jeffers was "an especially vulnerable victim."

"Dontel was a very lively, cheerful, and special child," his aunt, Phillipa Jeffers, wrote in a pre-sentencing statement. "There is nothing more difficult to accept than the unexpected death of my nephew ... Dontel is gone but not forgotten. I will always love Dontel Jeffers."

Stephen's lawyer said he'll likely appeal the conviction. Stephen will serve her time at MCI Framingham.