the Open Society Foundations.

As well as surveys of those who took part in the disorder, the research will include interviews with residents, police and the judiciary, and an advanced analysis of more than 2.5m riot-related Twitter messages.

The project is based on a groundbreaking survey conducted in the aftermath of the Detroit riots in 1967 by the Detroit Free Press newspaper and Michigan's Institute for Social Research. The professor who led the Detroit study, Phil Meyer, is advising the research into the disturbances in England. LSE's involvement will be led by Professor Tim Newburn, head of the university's social policy department.

A month after the disturbances began in Tottenham, north London, the Guardian can also reveal:

• More than 90% of the cases being sentenced at crown court are resulting inlong before a protest over the killing of Mark Duggan by police descended into a riot. An email warning from a senior community adviser to police was sent to the borough commander 24 hours before the protest took place. She went on holiday the following day.

Magistrates courts have been delivering sentences about 25% longer than average, according to the Guardian data. The difference reflects the greater sentencing powers of crown courts, and potentially also the severity of riot-related cases transferred to the higher courts.

The most severe sentences relating to the riots were handed to Perry Sutcliffe-Keenan and Jordan Blackshaw, both from Chester, who received four years for inciting riots in their home towns of Warrington and Northwich on Facebook. None of the messages posted by either individual led