The sentence seems stiff considering the CDC says biting "is not a common way of transmitting HIV." In all recorded cases, the blood of the HIV-positive person was involved as well as "severe trauma with extensive tissue tearing and damage."
Jamerson's threat to use the virus as a weapon could suggest he might try do so in other ways.
Jamerson was a drifter who is also diagnosed with schizophrenia.
He was arrested for sleeping under the I-395 bridge and was on his way to jail when he tried to escape and the attack took place.
Jamerson seemed to have slipped through society's cracks, where it's often difficult for homeless people to get treatment for HIV or mental illness. In prison, he'll receive treatment, including lifesaving drugs for the HIV and some treatment for his mental condition. It might not be the best treatment available, but it's probably better than the treatment, if any, he received while living under a bridge.
Of course, if society were more proactive in not letting schizophrenics fall through the cracks and made HIV treatment more available, this whole situation might have been avoided.