Final answer:
Alfred must serve at least eight years before parole eligibility due to mandatory minimum sentencing laws which are strict guidelines judges must follow when sentencing.
Step-by-step explanation:
Alfred is required to serve at least eight years before he is eligible for parole because of mandatory minimum sentencing laws.
These laws set minimum sentences that judges must adhere to, regardless of other factors such as the prisoner's behavior.
Such laws were part of the tough-on-crime reforms of the 1980s and 1990s, which aimed to reduce crime through stringent sentences, often leading to overcrowded prisons and increased state debts due to the need for more prison facilities.