A fingerprint from an old break-in solves a murder at the same factory months later. Elsewhere, a DNA spray means police can finally apprehend a prolific motorbike thief.

A hotel guest book gives police the names of an international drug smuggling network, and thieves who stole £20,000 of food from a factory are caught out by a car number plate.

A fingerprint on a fish and chips wrapper places a gunman in a rural location miles from his home, and a man’s laptop reveals that he is behind a luxury gift card fraud.

Fingerprints found after a break-in and brutal beating are enough to convict a man of murder, and crooks who burgled a man's home and started using his credit card are caught by CCTV.

Blood spatters found on a trench coat belonging to a suspect in an unrelated case of armed robbery links a callous killer to the murder of a wealthy pensioner.

A few spots of the victim’s blood on a blue shirt convict a murderer, and a rapper incriminates himself when videos he posts online about his drug dealing are seen by the police.

A blood-spattered hammer is the key to charging the prime suspect in a murder case, and a drug gang is brought down when one detective focuses on how the product is packaged.

A USB stick with information about illegal drugs is found at a respectable businesswoman’s house, and police crack down on the conversion of guns designed to fire blanks.

A single piece of paper found on top of a hidden fax machine gives police the number of a shipping container used to smuggle millions of pounds' worth of drugs from Thailand.

A hammer contaminated with the DNA of both victim and killer helps police solve a murder investigation, and a burglar is caught after photographing himself at the crime scene.

A man is linked to a series of murders by a shoelace with his final victim’s DNA on it, and coded information in a spreadsheet reveals the perpetrator of a campaign of blackmail.

An ice pick is recovered from the roof of a pub and brings a murderer to justice, and an anonymous letter throws suspicion on a man who may be storing and manufacturing guns.

A car hidden deep within a scrapper’s yard unlocks the riddle of a suspected gangland shooting, and police secure the UK's first conviction for modern day slavery at a car wash.

A few specks of grey paint help to solve two brutal axe murders, and a bungling burglar is caught when his DNA is found on a rock used to smash a window at one of his break-ins.