A discarded gun cartridge helps the police to convict a man who gunned down a fellow officer, and a packet of medication helps to lock up a gang of violent jewellery thieves.

A simple business card reveals the true identities of a gang of con artists, and a ripped-up, handwritten note holds the key to locking away two murderers.

A grainy video from a petrol station forecourt helps convict a gang of cold-blooded killers, and a criminal's mobile phone finally connects an unscrupulous gang targeting the vulnerable.

How a distinctive wallpaper pattern exposed the lies of a con-woman who claimed to be suffering from a rare cancer. And a hidden compartment in a car holds the key to convicting a gang of stealing hundreds of thousands of pounds from UK charities.

A distinctive sticker on a laptop finally links a man to a string of burglaries that had terrified an entire community, and a shiny copper hair dye puts a dangerous armed robber behind bars.

A distinctive hat leads police to a prolific gang stealing bank cards, and one careless text message puts a dangerous stalker behind bars for the longest sentence in a police force's history.

A hoodie helps police take a dangerous attacker off our streets, and a car's satnav reveals the mastermind behind the biggest armed robbery ever to hit Devon and Cornwall.

A vehicle's satnav puts a pair of prolific animal thieves behind bars, and an anonymous letter holds the key to the identity of a blackmailer on a mission to poison babies.

A wedding video helps crack the case of a teenage abduction, and an expired pilot's licence exposes a fraudster flying under the radar.

A scribbled name in a discarded notebook is the key to putting a dangerous driver behind bars, and the serial numbers on stolen bank notes crack the mystery of a dangerous gang wreaking havoc in the capital.

A plastic bag heat sealer convicts an online drug trafficker, and a casual chat with a criminal, plus a map, join the dots to catch three burglars terrorising a neighbourhood.

How a single glove reveals the identities of a prolific and violent gang, and an image of a distinctive ponytail solves a hi-tech bank heist.

How a discarded scrap of paper found in a household bin helps convict a cold-blooded killer; and a distinctive mole holds the key to tracking down a dangerous and predatory attacker.

A regular pair of pyjamas reveals the shocking true identity of an attacker who left his victim for dead, and a bright yellow baseball cap puts a daylight robber behind bars.

A single text message, hidden amongst thousands, nails a serial fraudster; and an extraordinary surveillance operation leads straight to the kidnappers – and their hostage.