Bill No. B296-32 [pdf] has been signed into law in Guam. As per Section 2, the police "shall issue a license" if the applicant meets the requirements, which are fairly lenient. Aside from being legally eligible to own a gun, applicants must show some proof of training, which can be a hunter safety course, any NRA course, or a DD214.
More at Guns Save Lives.
More at Guns Save Lives.