11 hours ago Sima Kotecha Senior UK correspondent Corbis via Getty Images Prison killings and violent assaults have increased in recent years "If you want to kill someone in prison, it's not difficult," a prisoner messages me from his cell. He's been convicted of serious violence and is serving a lengthy sentence inside one of England's largest Victorian prisons. "People in here are innovative - they have time to think about how to kill and damage," he says in a stream of messages to me. "You'd be surprised what they can do with razor blades and a toothbrush. The look of it [the weapon] is enough for you to panic." Possessing or using a mobile phone in prison is a criminal offence in the UK, but like many inmates, this prisoner has smuggled one in. The man, who is adamant he's remorseful and wants a fresh start once back on the outside, messages after news of the death of Ian Huntley rippled through Britain's prisons - and the country.…