Heald

In the novel Evil Under the Sun, Heald is a member of the Devon police called upon to help in the investigation into the murder of Arlena Marshall on Smugglers' Island. He established that the letters that Kenneth Marshall claimed to be typing on the morning of the murder could not be typed in less than an how and would probably take even longer if one had to stop to think. This served to confirm Kenneth Marshall's alibi.

Heald's rank and position is not clear. He could be a constable tasked with conducting the experiment on typing the letters or a forensic expert.