The FBI performed a record number of background checks on people who wanted to buy guns in December and all of 2012, CNN reports .
The spike this month – 2.8 million background checks – occurred during two high-profile mass shootings.
The number of background checks for the years totaled more than 19.5 million, an increase of more than 3 million, according to CNN.
Federal law requires background checks of anyone who wants to buy a gun.
The search is to ensure prospective owners don’t have a criminal record or a serious mental illness.