There is a crisis of trust around our ability to prosecute rape - an extraordinary admission from the Director of Public Prosecutions today, who vowed to win back trust.

One of the critical issues is how the criminal justice system handles evidence on mobile phones.

Tonight, a Channel 4 News investigation can reveal there are more than 21,000 digital devices held by police across the country, involved in crimes including rape and sexual assault, which are waiting for forensic analysis. And it's a backlog that has huge implications,