The FBI will take over the investigation of a St Louis police officer who fatally shot an unarmed teenager on Saturday.
Tom Jackson, chief of police in Ferguson, where 18-year-old Michael Brown was shot dead, said he welcomed the decision to bring in the FBI to examine the incident. The move followed a request by Jay Nixon, governor of the state of Missouri.
Brown, who was walking to visit his grandmother, was shot several times following an altercation with a police officer.
Rioting erupted in Ferguson last night following a candlelight vigil, with 32 people arrested. A further protest outside Ferguson police headquarters was held today.
More top news
Authorities have warned that the death toll is likely to rise as much of the building is yet to be searched.
The PM will sound out the possibility of new free trade agreements with Gulf states for once the UK has left the EU.
In the unexpected announcement on Monday, Mr Key said it was the "right time" to leave politics.