Denny came to the attention of the police on the 28 December 1888 because he matched the description George Hutchinson gave of the Ripper. Hutchinson had described a man seen with Mary Kelly shortly before she was murdered, wearing an Astrakhan trimmed coat. Denny was arrested after been seen accosting women in Kings Cross while wearing a long Astrakhan trimmed coat. He was described as 20 years of age, 5ft 6" tall, with a fair complexion, slight moustache and very curly hair. His address was given as 64 Myddelton Square, Clerkenwell. Denny was able to prove he was elsewhere at the time of the Whitechapel murders and was released.