President Joe Biden is launching a renewed effort to tackle crime in the US, as a series of major cities experience spikes in violent offences. Police departments define violent crime in slightly different ways, but the data usually includes murder, robbery, assault and rape. There were 25% more murders recorded in 2020 than the previous year. Major US cities have tended to follow the national trend in becoming safer since the 1990s, but some have recently seen a sharp rise in murders. Spikes in the biggest cities are a considerable concern to Biden's administration, with Chicago having the worst records for murders and a continuing upward trend in 2021. A rise in the number of shootings in many major cities runs parallel with the president's attempts to strengthen firearm regulations to combat gun violence. The administration hopes strong action now can stem the violence and prevent murders increasing further this summer.