Patrushev delivered this remark on Tuesday when asked by reporters who was behind this act of terror, Ukraine or ISIS.
"Ukraine, of course," Patrushev replied.
On March 22, a group of armed terrorists stormed into the Crocus City Hall concert venue, gunning down dozens of people and throwing incendiary devices around.
The shooting spree and ensuing blaze that spread across the building claimed the lives of at least 139 and left over 140 people injured.
The perpetrators then made an unsuccessful attempt to flee towards the border with Ukraine but were intercepted and apprehended by Russian security forces.
The terrorists were brought in alive and are currently awaiting trial while Russian authorities conduct a thorough investigation to identify everyone responsible for this act of terror.
*ISIS, also referred to as ISIL and IS, is a terrorist organization outlawed in Russia and many other countries.