Here’s a history of what happens after governments have disarmed their citizens:
1911 – Turkey disarmed its citizens, and between 1915 – 1917 they murdered 1.5 million Armenian
1935 – China disarmed its citizens, and between 1948 – 1952 they murdered 20 million Chinese.
1956 – Cambodia disarmed its citizens, and between 1975 – 1977 they murdered 1 million Educated people.
1970 – Uganda disarmed its citizens, and between 1971 – 1979 they murdered 300,000 Christians.
I guess the criminals did not turn their weapons in. Only the innocent law-abiding citizens turned in weapons.