The death penalty is provided for by the Criminal Code...

The death penalty is provided for by the Criminal Code and the legislation on civil disturbances for armed robbery, murder, treason, and offenses against the State.
On February 27, 1999, former military ruler General Olusegun Obasanjo won the presidential elections, and Nigeria resumed membership of the Commonwealth on May 29, when the elected government took power to end 15 years of military rule in the country. Nigeria was suspended from the Commonwealth in 1995 after late dictator Sani Abacha ordered the execution of Ken Saro-Wiwa and the Ogoni minority rights activists.
President Obasanjo had faced a death sentence for allegedly plotting a coup in 1995, but instead was sentenced to 15 years in jail and only released after the mysterious death in 1998r of Nigeria's then military ruler, General Sani Abacha. Obasanjo, who himself benefited from that pardon, had on assuming office as president in May 1999, ordered the release of all prisoners awaiting trial for offenses not including murder, robbery and other under the "serious category.
"The northern Nigerian states of Zamfara and Sokoto have adopted Islamic sharia law in October 1999. The practice includes crucifying or nailing a convicted armed robber to the cross, stoning to death an adulterer, giving life imprisonment to convicted robbers who did not steal property or kill and amputating the right hand and the left foot of those who stole but caused no loss of life. Zamfara state and other proponents of sharia have given assurances that non-Moslems will not be tried under the law but many non-Moslems say sharia violates Nigeria's constitutional status as a secular state.
Ten northern Nigerian states have adopted the Sharia code. Though the code is unacceptable to the national government, it appears helpless to deal with it because the 1999 constitution, hurriedly drawn up by the last military regime, is ambiguous on the code.