Death sentences for crimes such as murder are usually...

Death sentences for crimes such as murder are usually carried out by hanging, but firing squads are sometimes used to kill armed robbers and convicted traitors. Sharia law prescribes death by stoning for adultery and amputation for theft.
Northern Nigerian states began in reintroduce Sharia law after President Olusegun Obasanjo's 1999 election brought to an end 15 years of military rule. The law's return - it had been in use throughout the period of British colonial rule until Nigeria's independence in 1962- provoked bloody riots between Muslims and the region's Christian minority.
Human rights' groups have complained that these religious laws are archaic and unjust, and create an atmosphere of intimidation against Christians - even though they are not subject to the Sharia. On the other hand, local politicians and religious leaders say that crime has dropped sharply in the Sharia states.
The pressure group, the Community Development and Welfare Agenda, has said Sharia court decisions were a "fundamental assault on the sovereignty and legality of the Nigerian state", because they undermine the national, secular legal system.