Alan Wiggins survived until just past his third birthday, the machines keeping his fragile body alive and the tubes keeping him nourished. Wiggins never spoke a word, never took a step and had barely had any brain activity since he was 10 weeks old.

The little boy died last week in a Fairfax County nursing home, nine months after his father was released from prison for violently shaking him into an ultimately deadly coma. Because Alan clung to life for so long, his father avoided a murder charge and is now free after serving slightly more than two years behind bars.

Prosecutors call Alan's case a particularly difficult one, highlighting the horrors of shaken baby syndrome and the complications of prosecuting abused children's parents. Alan's fight for survival -- in which he never really regained consciousness -- put his father beyond the reaches of a murder conviction and left the baby in a debilitating state that took more than 2 1/2 years to kill him.

"It's just a horrible situation," said Prince William Assistant Commonwealth's Attorney Claiborne T. Richardson II. "It's such a sad thing."

Wiggins was shaken April 6, 2000, by his father, Cecil "Scott" Wiggins, now 36. Wiggins was left in his Woodbridge townhouse with the baby and his fiancee's two other children when she was hospitalized for trying to commit suicide. Wiggins, who wasn't used to caring for the children, said in interviews in 2000 that he was struggling.

Wiggins and authorities gave vastly different stories about what happened to Alan that day. Wiggins said he lightly shook the infant to revive him after a fall out of his car seat onto a carpeted floor. Police said Wiggins violently shook the baby in rage as he was trying to get him to stop crying.

Medical reports sided with authorities, as the infant had all the trademark signs of having been shaken, including severe brain injuries. Because infants' heads are large and their necks are weak, strong rotational forces slam their brains up against the inside of their skulls, causing catastrophic damage.

Wiggins said that he never intended to hurt his son and that he never wanted anything bad to happen to him. Wiggins could not be contacted for this report.

"I don't care what happens to me as long as my baby lives and comes out of this okay," Wiggins said in April 2000 as he leafed through snapshots of the infant. "I love my son very much. He means the world to me. All I can do is pray to God that Al makes it."

Part of the dilemma in the decision to keep Alan alive was the fact that his survival played a key role in how authorities proceeded against Wiggins. Had the baby died shortly after the attack, prosecutors said, Wiggins surely would have been charged with murder, as others have been in Prince William County. He would have faced a sentence of more than 20 years in prison.

But Wiggins and his fiancee held out hope for Alan and wanted to keep him alive. The baby survived, barely, when taken off a ventilator, and Wiggins was charged with felony child abuse. Wiggins pleaded guilty and was sentenced to two years and four months in prison.

"Sometimes you wonder if there is any just punishment for someone who causes such terrible injuries to a child," Richardson said. But because the baby was alive, prosecutors were limited in prosecuting Wiggins. And once a year passes after injuries are inflicted, Virginia law prohibits elevating the charges to murder.

Wiggins was released from state prison in May, having served his required sentence. His son lived another nine months before succumbing to his injuries. Authorities said Alan continued to grow but his brain didn't develop, a condition that almost inevitably leads to death.