Frank Spiggot was a police officer in the Uva Beta Uva system. When he met the Fourth Doctor and Romana II on the Rock of Judgement, he said he was looking into anomalies in the computer system. However, he was really looking into the murders of a mining team on Planet Eleven. The environmental engineer had been psychokinetically crushed to death, and the only person who killed in that manner was Xais. But since Xais had been executed on the Rock three years prior, Spiggot was trying to find out if she might be alive.
As Xais had imprinted her brain patterns in a helicon death mask, the Doctor gave Spiggot a formula to render the helicon inert, eliminating any remnants of Xais' mind. (PROSE: The Romance of Crime, AUDIO: The Romance of Crime)