Chief Inspector William Anderson was a police officer in the Lothian and Borders Police, stationed at Waverly Road. He has a wife who is a known adulteress, and had a son Andrew who left home early. He is described as 'stick-thin'.

In 1988 he was put in charge of the case of the Edinburgh Strangler, a serial killer who abducted and then murdered young girls. He put together a team including Gill Templer, John Rebus, Jack Morton, Inspector Hartley, and Gemmill, who he put on searching door to door and MO files. He gained a lead when he got Rebus to cross reference all the car sightings, and discovered the murderer most likely drove a pale blue Ford Escort. Also, the post mortem of the third victim showed that a knot had been tied in the garrotte used to strangle her, suggesting a possible military background. However when the Strangler abducted his fifth girl, William Anderson's son was also found strangled. He was ordered off the case, but wanted to stay and observe until its conclusion. When it surfaced that the killings centred on John Rebus, Anderson tailed him to the library where the Strangler worked under the name of Ian Knott. After finding Rebus wounded, they followed the suspect to the cells beneath the library where Anderson was knocked unconscious by him. However he recovered.