Hawaii County prosecutors will seek a life sentence for a 29-year-old Puna man found guilty of manslaughter yesterday in the 2005 death of Sarah Fay, who was brain-dead but kept on life support until her baby was born.

A Big Island jury found Marwan Timothy Saad Jackson, who was on trial for second-degree murder, guilty of the lesser crime. Manslaughter carries a 20-year maximum sentence. Second-degree murder carries a life sentence with the possibility of parole.

Deputy Prosecutor Charlene Iboshi, who will succeed Big Island Prosecutor Jay Kimura in April, said prosecutors will seek an extended term — life imprisonment — for the manslaughter conviction.

"This is a violent career criminal who has four other convictions," Iboshi said. Jackson was on probation for three felony convictions, including first- and second-degree assault, when the beating death occurred.

The 34-year-old Fay was 7 1/2 months pregnant with Jackson’s child when she was found unconscious with head and bodily injuries Nov. 25, 2005, at her Fern Acres home. Fay was pronounced brain-dead two days later.

Queen’s Medical Center doctors kept Fay on life support for 18 days until her baby boy, Josiah Darcy Fay, was delivered by Caesarian section, weighing 3 pounds, 5 ounces, on Dec. 12, 2005.

Jackson testified Fay fell twice while they argued on Thanksgiving Day, Nov. 24, 2005, once hitting a coffee table and a second time they fell together, with Fay receiving a black eye when her head hit his elbow, said Deputy Prosecutor Kanani Laubach. He also testified Fay told him she fell down a short flight of stairs the next morning.

But retired Honolulu Medical Examiner Dr. Kanthi De Alwis testified that all Fay’s injuries could not have come from a fall because she had multiple points of impact, including neck injuries that could not have come from falling, Laubach said.

 CORRECTION: Josiah Darcy Fay, whose mother was kept on life support so that she could give birth to him after she was declared brain-dead, was born Dec. 12, 2005. A previous version of this story yesterday reported the date was Dec. 13.