CHRISTOPHER STEVENS: 'Meet Dr Gallop, the modern forensic scientist with a taste for Sherlockery'

Cold Case Forensics: The Death of God's Banker (ITV1) 

Rating: Four stars out of five 

True crime is all very well. But for fans of the Golden Age of detection, it can be a little mundane. Where are the eccentric geniuses, the feats of memory and imagination, the sheer Sherlockery?

Meet Dr Angela Gallop. She’s a mistress of deduction in the classic mould, to the tips of her brilliantly varnished fingernails, their colours carefully matched to her clothes. She is also an internationally renowned forensic scientist, who has scrutinised some of the most notorious murders in recent criminal history.

Cold Case Forensics: The Death Of God’s Banker is the first in a series that sees Dr Gallop reconstruct her investigations, walking us through every step of her analysis and explaining the clues that help her create a vivid mental picture of how each murder was committed.

It’s like listening to Poirot’s thought process, before he gathers the suspects in the drawing room to unmask the killer.

To prove that Italian banker Roberto Calvi, found hanged from scaffolding beneath London’s Blackfriars Bridge in 1982, did not commit suicide (despite the Met’s first assumptions), Dr Gallop rebuilt the makeshift gallows in her own back garden.

Then she persuaded a younger colleague named Phil to clamber along the poles wearing a suit and leather office shoes, his pockets weighted down by rocks, until he reached the furthest beam, where the victim was found dangling.

Phil was willing enough, but it must have occurred to him, as he clung to the rusty metal bars 10ft up, that it’s always Sergeant Lewis who does the undignified legwork, never Inspector Morse.

Seizing Phil’s shoes, Dr Gallop immersed them in river water for hours, then examined the soles under the microscope to prove that flakes of paint and rust were indelibly embedded. The victim’s own shoes showed no such traces – so he couldn’t have climbed along the poles.

The time of death was indicated by Calvi’s wristwatch, which stopped while he was dangling up to his waist in the Thames. Studying the tide tables, a decidedly Holmesian touch, she deduced that he didn’t reach the scaffolding by walking on the shore.

Eliminate the impossible, as the Great Detective himself once said, and what remains must be the truth. The banker didn’t climb to his death. He didn’t walk. Ergo, someone put him there.

This logical process was immensely satisfying. It’s a pity that the programme was not executed with the same vigorous imagination, because most of the budget appeared to be blown on a trip to Rome. There, Dr G interviewed an Italian expert on organised crime whose accent was so pronounced, even the subtitles needed subtitles.

The rest of the show consisted of talking heads: former coppers and crime reporters, sitting bolt upright in front of the camera like schoolchildren in the headmistress’s office. Dr Gallop must have that effect on people, even the innocent ones.