A chilling look at the crimes of Stephen Port, the east London serial killer who poisoned four young men with lethal doses of a date rape drug.

A chilling look at the crimes of Stephen Port, the east London serial killer who poisoned four young men with lethal doses of a date rape drug.

A closer look at the crimes of Steve Wright, who was dubbed 'The Suffolk Strangler' after murdering five women in Ipswich in 2006.

A closer look at the crimes of Steve Wright, who was dubbed 'The Suffolk Strangler' after murdering five women in Ipswich in 2006.

An inside look at the series of mysterious deaths that occurred at the Stepping Hill Hospital in Stockport, Greater Manchester, in 2011.

An inside look at the series of mysterious deaths that occurred at the Stepping Hill Hospital in Stockport, Greater Manchester, in 2011.

Examining the murder of EastEnders actress Gemma McCluskie, who was killed by her older brother in the east London flat they shared in 2012.

Examining the murder of EastEnders actress Gemma McCluskie, who was killed by her older brother in the east London flat they shared in 2012.

The tragic story of Ann Maguire, who was stabbed to death by a pupil while teaching a Spanish lesson at Corpus Christi Catholic College in Leeds.

The tragic story of Ann Maguire, who was stabbed to death by a pupil while teaching a Spanish lesson at Corpus Christi Catholic College in Leeds.

For the first time since the terror attack in May 2017, we hear from the survivors, victims' families and emergency responders about that tragic night.

For the first time since the terror attack in May 2017, we hear from the survivors, victims' families and emergency responders about that tragic night.