We had.our.lowest crime.rates.before 1968. Why be careful with the truth!
Because truth is very subjective. Look at the situation in the United States in the 1960's. We were fighting a very unpopular war, racial tensions were simmering over, and we had different ideas on policing and sentencing than we do today.
It is impossible to prove that low crime rates are solely due to gun laws (or the lack thereof).