Digital devices such as smart doorbells, dashcam footage, car GPS systems and even Amazon Alexa are providing increasingly more evidence in criminal trials in the United Kingdom, a top prosecutor at the Crown Prosecution Service (CPS) said on Monday.

The CPS represents India in extradition cases that have recently seen video footage of Arthur Road jail in Mumbai, where individuals sought by India are to be lodged, while witnesses from India have deposed digitally through video links.

Max Hill, director of public prosecutions, said developments in digital technology are driving significant changes in the way evidence is collected and used in UK courts.

He said: “As little as 15 years ago, criminal investigations and subsequent prosecutions were likely to focus on the crime scene for evidence backed up by eye witness testimonies and door-to-door enquiries”.

“This has been transformed by the way we now live our lives and share information online. The digital devices which are becoming part of the fabric of everyday life, like smart phones, social media and even things like Alexa can actively provide key evidence to pinpoint whereabouts, provide footage of an incident or a timeline”.

“Alexa has already been used as a line of enquiry in a murder case the US. The opportunities and threats presented by the digital age is a constantly evolving challenge for all parts of the criminal justice system, as well as for wider society,” he told the Westminster Policy Forum.

He cited an example of how the GPS system in a Land Rover Discovery was instrumental in providing evidence during a crossbow murder case earlier this year. Following the death, the defendant was questioned about his possession of crossbows, but it was only two week later when the GPS system was retrieved from his partner’s burned-out vehicle that vital evidence was found.

Information retained by Jaguar Land Rover proved the car had been used for reconnaissance as it was traced to the victim’s driveway the night before the murder. It also showed that the car had travelled to the crime scene again the following night and remained until 12 minutes after the victim was shot.

The system indicated the boot was opened and closed when the car arrived and before it left. The offender was convicted and received a life sentence.

Hill added: “The detectives of the past could only dream of the modern opportunities to gather and deploy evidence. But these also represent unprecedented evidential challenges. Just as technology is changing the nature of crime, technological innovations will change investigations”.

“Machine learning and artificial intelligence is being developed to be more effective and reliable in sifting through vast amounts of data…This is a fast moving landscape and we will not and must not stand still.”