Can I still be hired as a Police Officer
if I've used drugs in the past?
There is no one answer to this. Disqualification from police hiring due to drug use will be based on each department's hiring guidelines.
You should research the qualifications for departments you would like to test with.
Many departments identify drug use into two categories: soft and hard drugs.
Narcotics such as Marijuana and hash are often considered soft drugs.
Cocaine, Crack, Heroin, Meth LSD, are considered hard drugs.
Many departments will have a required time frame of no use, from the last time you used to the time of application. An example could be 3 years of no use for soft drugs and 5 years of no use for hard drugs.
If you are not within the time frames identified by a department, do not lie about it. It will come up during your polygraph, and if you are found to have departed from the truth "lying," you will be disqualified.