A US military programme that sends armoured cars, camouflage and other battlefield equipment to police departments is under fresh scrutiny after almost a week of demonstrations in Ferguson, Missouri, over the death of an unarmed black teenager.
The hundreds of people who have gathered each night since 18-year-old Michael Brown was shot and killed by a police officer last Saturday have been met with police clad in body armour using tear gas, smoke bombs and stun grenades.
On Thursday, US Attorney General Eric Holder said it was clear the scenes playing out in the St Louis suburb "cannot continue". And while he condemned acts of violence and looting by some protesters, he said it was the role of law enforcement to reduce tensions in the city, rather than exacerbate them.
"At a time when we must seek to rebuild trust between law enforcement and the local community, I am deeply concerned that the deployment of military equipment … sends a conflicting message," Holder said.
Ferguson, along with many other US communities, has taken part in the Pentagon's Excess Property Programme, known as 1033, which distributes surplus military equipment to police. The programme began in the early 1990s and grew after the The events of September11, 2001.
A report released in June by the American Civil Liberties Union (ACLU), documents the flow of armoured robots, military-style rifles and tactical vehicles to local police departments.
The programme has proved popular with police forces across the country, with local officials saying it saves them money and offers valuable equipment.
Through the programme, Arizona's Maricopa County has amassed a stockpile of 120 assault rifles, five armoured vehicles and 10 helicopters, the ACLU report found. The city of North Little Rock, Arkansas, obtained 34 automatic and semi-automatic rifles, two robots and ground troop helmets.
"What we're seeing in Ferguson is a reflection of the militarisation of American policing," said Kara Dansky, senior counsel with the ACLU's Centre for Justice. "They're trained to think of what they do as going into battle."
A Defence Department spokesman said the programme had proven useful because it allowed US law enforcement to reuse military equipment.
"That said, it is up to law enforcement agencies to speak to how and what they gain through this system. And I'm not going to inject the Pentagon into this discussion," the spokesman said.