CAIRO—An Egyptian court sentenced the former interior minister who oversaw the expansion of the Mubarak regime's vast security apparatus to 12 years in prison for corruption, in the first conviction of a senior former regime official since a popular uprising drove President Hosni Mubarak from power.

The ruling Egyptian military appears intent on showing Egyptians it is responding swiftly to their demands for the trial of former officials, and to placate the popular anger that fueled the 18-day uprising that toppled the regime in February.