A traffic collision leads police to a cold-blooded killer. A casino gambler proves to be the key to a money-laundering scheme, and a speeding motorbike leads police to a prolific burglar.

A stop-and-search leads to the arrest of a serial killer, a copper’s decision ends in an armed stand-off, and a road traffic collision cracks open a massive fraud case.

A one-off burglary puts police on the trail of a gang stealing luxury cars to order – and in search of an international fugitive. And when a bank worker is approached on social media, it rings alarm bells and helps bring down a major fraudster and identity thief.

A seemingly accidental house fire leads detectives to snare a killer. And a van pulled over for having a cracked windscreen turns out to contain a massive cannabis stash.

A suspicious bag handover leads investigators to expose a major money-laundering gang. And police called to a road accident soon realise they’re dealing with a case of murder.

What looks like a devastating burglary of family heirlooms proves to be a sham and exposes the so-called victim as a million-pound fraudster. And when police stop a suspicious-looking car on a hunch, they end up bringing down an unscrupulous drug dealer.

A car that fails to stop for police turns out to be behind a life-threatening hit-and-run. And a single fake cheque is spotted by a sharp-eyed bank worker and puts investigators on the trail of a gang of con artists.

A 999 call about a possible intruder puts police on the trail of a violent attacker. And a traffic stop on the other side of Europe helps police in Bristol solve a burglary crime wave much closer to home.

Police called to do a welfare check on a missing man end up hunting for a double murderer. And an officer on his day off spots a car he knows belongs to a disqualified driver. His investigation not only catches a serial driving offender but a man with a whole load of Class A drugs.

When a car is caught running a red light, police find themselves chasing an armed criminal. A suspicious death leads to the discovery of a deadly plot to poison a man.

An anonymous tip-off leads authorities to crack the UK’s biggest case of food fraud. A copper’s instinct uncovers a conspiracy to commit a massive insurance fraud, and a faulty brake light leads to police arresting two high-level drug dealers.

Antisocial behaviour helps solve a string of terrifying robberies, a disturbance reveals a massive haul of firearms, and a dodgy truck licence is the key to cracking a smuggling operation.

Two PCSOs are caught in a web of lies, a tip-off leads to police cracking a £2 million insurance scam, and a married couple rip off thousands of concertgoers.

A series of burglaries helps police to crack a drug-dealing conspiracy, a consumer complaint brings down a national fraud, and a jet-setting con-woman is brought to justice.

A doorstep distraction burglary leads officers to a violent serial offender. And police cracking down on drug crime uncover a huge fake ID factory serving criminals across the UK.

A suspicious solicitor is caught arranging sham marriages, a poaching complaint brings down an international smuggler, and a dodgy number plate ends in a high-speed pursuit.