David Tamihere could not simply “prove” innocence in the abstract; in a criminal case, the usual route is to show that the prosecution’s case is unsafe, incomplete, or unfair, and that a jury should not have convicted him beyond reasonable doubt. In his case, reporting around the long-running appeal says the Supreme Court found his original trial unfair and has quashed the convictions, with a retrial possible.

What would count as proof

The most persuasive ways to show he is not guilty would be:

  • A credible alibi showing he could not have been at the scene.
  • Forensic evidence that excludes him, such as DNA, fingerprints, or other physical evidence pointing elsewhere.
  • Reliable witness evidence that directly contradicts the prosecution case.
  • Proof that key testimony was false or unreliable , especially if it was central to the conviction.
  • Alternative suspect evidence that better fits the facts of the case.

Why this case is difficult

Public reporting says the case has long turned on a mix of circumstantial evidence and witness testimony, including testimony later challenged as false or unreliable. The Supreme Court’s March 2026 decision, as reported, focused on trial unfairness and the need for a jury to consider the changed evidential picture at retrial.

Practical legal reality

In real life, a defendant usually does not need to “prove innocence” outright. Instead, the defence tries to create enough doubt that the prosecution cannot meet the criminal standard of proof beyond reasonable doubt. If a retrial happens, the most important task is to test every major witness, every forensic claim, and any new evidence that may support a different account.

If you want the shortest answer

He would most likely need strong exculpatory evidence — especially alibi, forensic exclusion, or proof that the key incriminating testimony was false — to convince a court or jury he was not guilty.

If you want, I can also turn this into a short SEO-style “Quick Scoop” post or a plain-English timeline of the case.