A glance at the four main candidates in Nigeria's presidential elections Saturday:
The 53-year-old incumbent and ruling party candidate has been called an "accidental president." The soft-spoken marine biologist became governor of Bayelsa state after the impeachment of its elected governor. Jonathan later became vice president under elected Muslim leader Umaru Yar'Adua after a widely criticized 2007 election. Yar'Adua left Nigeria for Saudi Arabia in late 2009. A power vacuum stalled the country for months until lawmakers took an extraconstitutional vote to give Jonathan presidential powers in February 2010. Jonathan became president in May 2010 after Yar'Adua's death. Known for wearing the traditional caftan and bowler hat of his Niger Delta home, Jonathan is a Christian of the minority Ijaw ethnic group.
The 69-year-old former military ruler first came to power in a 1983 coup. His regime executed drug dealers, returned looted state assets and sent soldiers to the streets with whips to enforce traffic laws. His "war against indiscipline" won many followers, though his regime detained journalists critical of the government and laws were passed allowing indefinite detention without trial. Despite his recent assurances that he is a convert to multiparty democracy, some worry the perennial candidate could return to his autocratic ways. Still, Buhari, a Muslim, has drawn thousands to his rallies across Nigeria's dissatisfied north.
The 50-year-old former police official gained prominence in Nigeria after being appointed as the chairman of the Economic and Financial Crimes Commission by former President Olusegun Obasanjo. Ribadu pursued top politicians in the country, though critics say he targeted Obasanjo's opponents. Ribadu once estimated that corruption has cost Nigeria more than $380 billion since gaining its independence from Britain in 1960. After Yar'Adua came to power, officials reduced Ribadu's police rank. He fled the country in 2008 after what his lawyer described as a drive-by shooting. A Muslim from Adamawa state, Ribadu is the candidate of the Action Congress of Nigeria, the country's strongest opposition party, though his campaign has been plagued by missteps.
The 55-year-old former teacher and educator has served as the governor of Kano state in Nigeria's north. While governor, the typical hotbed of violence grew far quieter. However, under his administration his state saw officials stop giving polio vaccinations to the young over unfounded fears the vaccine was a Western plot to sterilize Muslims.