Appellant was convicted of first degree murder; the crime occurred on February 27, 1996. Although Penal Code section 2933.2 prohibits presentence conduct credits for murderers, its effective date is June 3, 1998 and it applies prospectively only. Appellant was entitled to conduct credit, but under Penal Code section 2933.1, effective on September 21, 1994, he earned conduct credit at the rate of 15 percent.