A defendant claiming a violation of his right to speedy trial must show that the delay impaired his ability to defend against the charges, and not just that he lost the opportunity to serve a concurrent term. The prosecution filed charges against petitioner, but did not notify him until he had completed a jail term in a neighboring county for a probation violation. Appellant did not contend that the delay prejudiced his ability to defend himself, but that he should be allowed to establish prejudice by showing that he lost the chance to serve any sentence stemming from the charges concurrently with the jail term he served on the probation violation. The California Supreme Court disagreed, holding that a defendant claiming a speedy trial violation under the California Constitution must show that the delay impaired the ability to defend against the crime charged for reasons such as witnesses who have become unavailable, fading memories, etc. If the defense makes that showing, the trial court may then consider a loss of opportunity to serve a concurrent sentence in weighing all of the prejudice against the prosecution’s reason for the delay. The Court disapproved the holding in People v. Martinez where the Court of Appeal found that the defense may satisfy its initial burden of establishing prejudice from the delay by demonstrating that the delay cost the defendant an opportunity to serve a sentence concurrently. The Court rejected appellant’s claim that to hold otherwise would encourage prosecutors to intentionally delay filing complaints, holding that there was no evidence that the prosecutor deliberately delayed here and that engaging in such improper conduct would violate the prosecutor’s duty to expedite criminal proceedings.