Legislation to set a mandatory three-day waiting period for handgun transfers and establish licensing and registration guidelines on the sale of binary target markers have been introduced.

The bills — HR.4018 and HR.4064 — were introduced by House Democrats last week and join a growing number of gun control proposals filed in the days immediately after a mass shooting in Las Vegas that left 59 dead.

U.S. Rep. Raja Krishnamoorthi, D-Ill., debuted his handgun waiting period bill Thursday to mandate that three business days elapse from the time a handgun transfer was initiated between a federal firearms licensed dealer and an individual. Limited exceptions would be allowed for loans of less than 30 days between immediate family members.

Florida Democrat U.S. Rep. Darren Soto filed his push against binary target marking compounds such as Tannerite on Friday. His measure would amend federal explosives laws to require dealers to be licensed and buyers to show identification for each purchase. It would also direct the Attorney General to establish a National Binary Explosive Check System to require all sales and transfers of binary markers to be entered and tracked, including the name and address of purchasers.

Further, the Department of Justice would set a monthly limit on the legal amount of compound that could be transferred to individuals, with criminal penalties for making false statements, unregistered purchases or exceeding the limit.

Police reportedly found several pounds of ammonium nitrate fertilizer in the car of the Las Vegas shooter, and tannerite in his home.

Both measures have been referred to the Republican-controlled House Committee on the Judiciary.

They join bills to ban bump stocks and magazines capable of holding more than 10 rounds of ammunition, expand smart gun mandates and funding for federal gun violence research, limit online ammunition sales, and report multiple rifle transfers.