The NSO under Shinkafi also dealt with matters of illegal immigration, one very controversial case was the deportation of Alhaji Abdurrahman Shugaba Darman, the house majority leader of the Great Nigeria People's Party (GNPP) in the Borno State House of Assembly over an alleged assassination plot against the president with the aid of Chadian refugees. Though Shagari denied that the deportation had anything to do with the alleged assassination plot, it had all the hallmarks of a political witch hunt. There was also the case of Alhaji Zanni Bukar Mandara, a military food contractor who was charged and convicted for treason. Alhaji Mandara had been complaining to some soldiers that the economy was no longer what it used to be and that the country was drifting to a point where a change was needed. Mandara was arrested and charged by the NSO for plotting to overthrow the government of President Shagari. Such sentiment was common at the time and Mandara was only unfortunate that his indiscretion was made in the company of soldiers.