Even with a certificate of probable cause, a defendant may not challenge his plea based on complaints that do not go to the legality of the proceedings as contemplated by Penal Code section 1237.5. After pleading no contest to second degree murder of a fetus and various drunk driving offenses, the defendant asked to withdraw his plea on the grounds that he had received ineffective assistance from his retained counsel. Counsel declined to file a motion to withdraw the plea, and the defendant was sentenced to prison. He obtained a certificate of probable cause and challenged his plea agreement on appeal. He argued that the court below should have allowed him to withdraw his plea in order to hire another lawyer in order to examine a contributory negligence defense. The Court of Appeal first held that the availability of a defense to the charges was an issue going to guilt or innocence and was not cognizable on appeal after a guilty plea. To the extent that the issue contained an allegation of ineffective assistance of counsel, the argument was not supported by the record. The Court of Appeal further rejected the argument on its merits, noting that contributory negligence is not a defense to a criminal charge. Finally, the Court of Appeal found that the preliminary hearing supplied an adequate factual basis to support a finding of implied malice due to the defendants numerous prior convictions for driving under the influence.