Petitioner Kennedy sought a writ of mandate commanding the trial court to grant 35 discovery requests pursuant to Penal Code section 1054.9, which allows person subject to a sentence of death or LWOPP to file a motion for postconviction discovery to assist in seeking a habeas writ. The appellate court concluded that petitioner was not entitled to relief. Seeking a discovery order under section 1054.9 requires proof that a defendant is entitled to materials he would have been entitled to at the time of trial, i.e. that the prosecution had a duty to disclose the evidence. Absent such a showing, the defendant cannot carry his proving of showing the trial court abused its discretion in denying the discovery request. Here, Kennedy did not show he would have been entitled to the materials he requested at the time of trial. He requested a broad category of materials, contending that they might include some otherwise unidentified evidence which would have been favorable by showing someone else committed the murder or serving to impeach prosecution witnesses. A plausible explanation does not suffice under section 1054.9; a defendant must identify the materials with sufficient specificity to show that he would, in fact, have been entitled to those specific materials at the time of trial.