Because Penal Code sections 790 (b) and 954.1, permitting consolidation of charges and eliminating mandatory cross-admissibality of evidence, address the conduct of trials, as opposed to changing the legal consequences of criminal behavior, they do not implicate ex post facto considerations. Alcala was originally convicted of an Orange County murder occurring in 1979. Judgment was reversed and he was again convicted and sentenced to death. This second conviction was reversed and he was returned for retrial on the charge. A grand jury indicted him on four other murders in Los Angeles which the prosecution charged with the original murder. Following the original murder, the Legislature passed section 790. With the now-five count murder charge, Alcala claimed that joinder of the first murder was error as its commission predated the enactment of the offense. The reviewing court determined that the trial court adequately considered the joinder of the first murder but failed to conduct the requisite individualized analysis of joinder of two others and ordered severance as to those two.