Killer dentist Colin Howell injected his lover with drugs to knock her out while they had sex and once feared he had overdosed her, a court heard today.

Double murderer Colin Howell went for a game of squash in the days after he killed his wife and his lover’s husband – and his mistress showed no emotion when told their bodies had been found, a court in the North heard today.

A jury was sworn in today at the start of a trial of a woman accused of murdering her policeman husband and her ex-lover’s wife in the North almost 20 years ago.