Some lw enforcement agencies with forensic labs may disqualify you and then there are others that would consider you. It is up to each agency as to whether you qualify per their policies. The same is true of independent forensic labs. you will need to contact the various labs you are considereing to determine whether will will be disqualified or not. Sometimes setting aside a conviction or expungement of a criminal record might be of benefit as might a presidential pardon. I recommend that you consult with your attorney.