

A cold case is any criminal investigation by a law enforcement agency that has not been solved for (generally) at least one year and, as a result, has been closed from further regular investigations. A cold case may be closed for various reasons such as: previously available technology was not able to adequately analyze the evidence in order to form a conclusion; witnesses were hostile and uncooperative; various time constraints hindered the investigation; the originally assigned detectives had a heavy workload; a lack of worthwhile leads stalled the case.
Below is a list of people suspected to be Jack the Ripper.