heila Keen-Warren thought she’d got away with murder. In 1990, her now-husband’s then-wife, Marlene Warren, 40, was shot in the face after answering her door. The only witness, Marlene’s 21-year-old son Joseph Ahrens, told how the killer was dressed in a clown costume, holding carnations and balloons – leading media to dub the murderer the “Killer Clown”. The trail ran cold for almost a quarter
