On patrol with a specialist knife crime unit as they take weapons off the streets.

A jaw-dropping chase in which a man drove a stolen car on to train tracks to flee police.

The incredible story of survival of a woman stabbed 29 times by her ex-partner.

How a killer finally went to prison after Britain's oldest case of double jeopardy.

The story of a brave officer and his dog injured by a man with a zombie knife.

How a search and rescue charity saved lives in the aftermath of the earthquake in Turkey.

How a gang who stole a collection of priceless books were eventually caught.

A cash guard talks down a gunman who was locked inside a shop with him.

How a homeowner almost had his house sold from under him by his tenant.

The incredible story of two officers stabbed during a routine search in a shopping mall.

On patrol with a specialist knife crime unit as they take weapons off the streets.

How a serial rapist who appeared on a reality TV show was eventually caught.

The brave officer who faced up to an armed suspect and arrested him despite injury.

The hunt to catch the teenager responsible for a spate of stranger stabbings in Bristol.

The story of a devastating crash caused by a lorry driver using his phone at the wheel.

Rav Wilding and Michelle Ackerley are live, asking for your help with unsolved cases.

Rav Wilding and Michelle Ackerley are live, asking for your help with unsolved cases.

Rav Wilding and Michelle Ackerley are live, asking for your help with unsolved cases.

Rav Wilding and Michelle Ackerley are live, asking for your help with unsolved cases.

Rav Wilding and Michelle Ackerley are live, asking for your help with unsolved cases.

Rav Wilding and Michelle Ackerley are live, asking for your help with unsolved cases.

Rav Wilding and Michelle Ackerley are live, asking for your help with unsolved cases.

Rav Wilding and Michelle Ackerley are live, asking for your help with unsolved cases.

Rav Wilding and Michelle Ackerley are live, asking for your help with unsolved cases.

Rav Wilding and Michelle Ackerley are live, asking for your help with unsolved cases.