Detective Chief Inspector Walter Dew (17 April 1863 – 16 December 1947) was a British Metropolitan Police officer who was involved in the hunt for both Jack the Ripper and Dr Crippen.

[1] Early in 1887, Dew was transferred to Commercial Street police station in H Division (Whitechapel), where he was a detective constable in the Criminal Investigation Department during the Jack the Ripper murders of 1888.

[2] In his memoirs, published fifty years later in 1938, Dew made a number of claims about being personally involved in the Ripper investigation.

"She was usually in the company of two or three of her kind, fairly neatly dressed and invariably wearing a clean white apron, but no hat.

"[3] Dew also claimed to have been one of the first police officers on the murder scene, though none of the records mentioning those people who were present list his involvement.

Dew wrote that he saw Kelly's mutilated body in her room in Miller's Court and that he regarded it as "the most gruesome memory of the whole of my Police career.

"[4] Dew wrote that Kelly's open eyes were photographed in an attempt to capture an image of her killer,[5] but police doctors involved in the case had already determined that such an effort would be futile.

[7] Despite receiving a seven-year prison sentence, Johnson refused to disclose the whereabouts of the Duchess' jewels, and only £4,000 worth were ever recovered.

Bache & Co. using the name Conrad Harms in 1909, and transferred funds totaling £1,637 14s to his bank account in London, where he subsequently fled, it was Dew who tracked him down.

Despite claiming that he was Harms' near identical cousin Henry Clifford, a pretence he maintained even when confronted by the wife he had previously abandoned, Friedlauski/Harms was sentenced to six years penal servitude for fraud and bigamy.

Meanwhile, his lover, Ethel Le Neve (1883–1967), moved into Hilldrop Crescent and began openly wearing Cora's clothes and jewellery.

Captain Henry George Kendall recognised the fugitives and, just before steaming out of range of the land-based transmitters, had telegraphist Lawrence Ernest Hughes send a wireless telegram to the British authorities: "Have strong suspicions that Crippen London cellar murderer and accomplice are among saloon passengers.

Dew boarded a faster White Star liner, the SS Laurentic, arrived in Quebec, Canada ahead of Crippen, and contacted the Canadian authorities.

Much of my time in Canada was spent evading reporters and cameramen, who knew all about my arrival in spite of our efforts to keep it secret, and who frequently became personal when I did not give them a statement.

As it happened, Crippen and his companion, Miss Ethel Le Neve, showed no desire to postpone our departure and waived their extradition rights, which enabled us to make the return journey after being only three weeks in Canada.

After his retirement, Dew became an unofficial 'criminal expert' for the British press, who would print his comments and opinions on various cases then in the public eye, such as the mysterious disappearance in 1926 of crime-writer Agatha Christie.

Walter Dew appears as a main character in Blackout Baby, a thriller by French writer Michel Moatti, published in 2014.