Knowing that you have a Master's in Criminal Justice in Homeland Security, you should be well positioned to start your career. However, since most legitimate recruiting firms do not charge the potential employees, it's not a bad idea. Be careful and research the company before signing up since there are some less ethical recruiters who just send out loads of resumes and spam employers. At best, they won't get you a job. Worst case, they will damage your reputation and block you from getting a job at some companies.
Best of luck!
It maybe worthwhile trying a few options and repeating/rinsing as required such as: creating a LinkedIn profile, networking/reaching out to alumni, past employers and colleagues and adding them as connections, creating job alerts, attending niche networking mixers/recruiting events and joining niche groups.
Good luck in your job search!
Recruiters are a thing of the past. You need to network with people you know and get them to introduce you to people you don't know and you need to check jobboards (like linkedin.com or indeed.com) daily. Also, if you want a job with homeland security, it might be worth a stint in the coast guard or military.