Can you join the police force if you are 31yrs?

Some law enforcement agencies have upper age limits for recruits, but there are rare. In most cases, anyone who is of the minimum age (usually 21) and otherwise meets hiring standards can be hired as a police officer.

Additonal: I don't recall what the age is but there IS an upper restriction on hiring age on some (all?) of the federal police agencies. It has to something to do with the minimum number years you must work in order to be eligible to retire and what your age would be at that time. If you are interested in the federal service, be sure to check out their recruiting information before becoming too interested in that particular agency.

More additional: Yes, there is an upper age limit for federal law enforcement officers. Because there is a mandatory retirement age of 57 for federal officers, most new applicants can't enter federal service after age 37. This is ensure that every new officer has the opportunity to work 20 years and earn a full pension. The age limit can be adjusted if the applicant has accumulated other credits for federal service, which can include time spent in the military.