Over the years in ‘Crimes That Shook Britain', we have covered some of the most infamous crimes that the nation has witnessed. From murders to bombings, from random killing sprees to cold hearted calculated abductions, we have shone a light on some of Britain's darkest times.In this special episode, we focus on those criminals who have been brought to justice for one crime only to be released to commit further terrible acts. We speak to legal professionals to discover if the system is at fault or have these killers exploited legal loopholes. We talk to victims and relatives of killers who preyed on their loved ones – if the perpetrators had been kept inside – would their loved ones still be alive? And we discuss with campaigners what can be done to ensure the justice system can both rehabilitate but also ensure our safety.