Proposition 57 created expanded parole eligibility for nonviolent felony offenders in California who have served the full term of their primary offense, and on paper your son fits that profile. Whether it meaningfully accelerates his release on an 18-month sentence with half time already built in depends on several factors.
With half time credit, he is already looking at serving about nine months assuming a clean record. That is the baseline without any Prop 57 benefit applied. The question is whether the parole board review triggered by Prop 57 eligibility produces an earlier release than that nine-month calculation.
His prior criminal history is the biggest variable. Prop 57 parole consideration involves a risk assessment that weighs the current offense, past record, behavior while incarcerated, and programming participation. A clean prior history and good institutional conduct strengthen the case significantly. A more complicated background makes the board more cautious regardless of the nonviolent nature of the current offense.
The sentence length itself is also a factor. An 18-month term is short enough that the parole board review process may not produce a dramatically earlier release date than the half-time calculation already provides. The administrative timeline of scheduling and conducting a review eats into potential savings on shorter sentences.
What your son can control is pushing the process actively. Getting to his counselor at DVI, making sure his Prop 57 eligibility is documented and moving through the system, and maintaining a spotless conduct record are the three things that give him the best shot at the earliest possible release date under the law.