Waldo was a circus strong man with a violent criminal history. He killed a man who tried to blackmail him by threatening to expose the secret of one of Waldo's past sins. Waldo then framed an innocent man for the murder, planting evidence in his caravan. Waldo's crimes brought him into conflict with heroes such as Sexton Blake and Nelson Lee. Later, Waldo was reformed and became a Deputy Commissioner of Scotland Yard, helped by Chief Inspector Lennard.