I am becoming a police officer and currently enrolled in Criminal Justice at a community college. No, having a criminal record does not automatically disqualify you from becoming a police officer, but it definetly doesnt help your chances. Almost all felonys will disqualify you, and a few high end misdemeanors. Violent criminal acts are the ones that will disqualify you suchas assault. This is because they dont want someone who has a past of violent acts in possession of a firearm.
To become a police officer, although it is not required, you should enroll in a 2 year Criminal Justice or Law Enforcement class at a local college and then pursue a police academy in your area and they will usually help you find a police department looking to hire new recruits. The school i am going to is a 2 year degree and the last 6 weeks of the program is Police Academy, and as soon as you get your degree you are already permitted to become a police officer in the state of Michigan.