A chest full of evidence

A DEVICE failing to explode properly might be one of the best scenarios for police.

When so much of the device remains intact, it provides a treasure chest of potential evidence.

Not just the opportunity for fingerprints and DNA, but the materials used and the way it was constructed can provide a signature that officers will use to point them to who was behind it.

CCTV from trains and in underground stations is comprehensive. Such a large item being carried will make finding the suspect easier.

Data from the entry barriers will be crucial as will the witness accounts.

We should be confident our counter-terrorism investigators will succeed.