Incredible photos show life of the front line for London's armed police officers as they fight against terrorism, gang culture and riots.
Sobering images show the brave men and women who put themselves in harms way to try and keep or restore peace in the UK capital.
London has seen its fair share of atrocities in recent years including terror attacks in 2017, London riots in 2011 and the murder of Lee Rigby in 2013.
The unsettling photos are included in veteran firearms officer Stephen Smith's new book London's Armed Police: Up Close and Personal - a behind-the-scenes look at the Met's Specialist Firearms Unit SCO19.
They show the work armed police do every day in vivid detail with explosions photographed from just feet away.
A dog and handler abseil down the tower at the Firearms Training Centre in Gravesend. Believe it or not, many of the dogs enjoyed the training, says author Stephen Smith. The centre was opened in 2003 to provide London's officers with firearms and public order training, which helps to maintain the Metropolitan Police Service's worldwide reputation as a leading law enforcement agency
The wrought-iron railings in to which Khalid Masood finally crashed his car following a killing rampage on Westminster Bridge in 2017. Officers and paramedics are seen giving medical attention to some of his victims. Some 50 people were injured, four fatally. Masood, 52, was shot dead by police after fatally stabbing PC Keith Palmer, 48, and ploughing into Kurt Cochran, 54, Leslie Rhodes, 75, Aysha Frade, 44, and Andreea Cristea, 31, in a rented 4×4, causing fatal injuries
Aftermath of the 2011 rioting and arson attacks that caused so much damage and misery, especially in London. The riots were sparked following the death of gang member Mark Duggan after he was shot dead by officers following a vehicle stop in Tottenham. An inquest jury found the 29-year-old was lawfully killed after armed officers stopped the minicab he was travelling in because of intelligence he was carrying a gun
Counter Terrorist Specialist Firearms Officer firing his SIG MCX weapons system on the range at Leman Street, the HQ of CO19. The SIG MCX series features a short-stroke gas piston system to reduce recoil and improve the reliability of the weapon. And SO19 is sometimes compared to American SWAT units
Fusilier Lee James Rigby, 25, 2nd Battalion, Royal Fusiliers who was stationed at the Royal Artillery Barracks Woolwich was murdered by Islamic terrorists in 2013. Last year Michael Adebolajo, 33, expressed remorse and 'regret' for murdering Lee Rigby and planned to write a letter of apology to the Drummer's family, according to prison sources
Armed Police Officers 'form up' at the side of the building while the door is breached by an explosive charge. For the most part, the police forces of the UK are unarmed. But they all have firearms units to provide the police force with the capability to deal with terrorists and armed criminals
The police officer on the left shoots one of Lee Rigby's attackers in the groin and thigh as he points a pistol at the officers. He is already collapsing to the ground. Michael Adebolajo, 29, and Michael Adebowale, 22, struck Fusilier Rigby with a car before hacking him to death. Adebolajo had claimed he was a 'soldier of Allah' and the killing was an act of war
Officers make use of cover on the tracks of the London Underground searching for a suspect who has fled into the tunnel during a training mission. It would be imperative that the power is turned off before using this tactic. There were just under 6,500 trained firearms officers in England and Wales at the end of March 2018.