Gun laws in Kentucky, where Donal J. Curtin Jr.'s 21-year-old son bought an AK-47 rifle in 2010 before giving it to his father, are much less restrictive than those in Massachusetts, where Curtin faces a series of weapons charges following a domestic dispute with his fiancee in July.

Curtin, 48, a longtime Braintree police officer, was arraigned in Quincy District Court on Oct. 21 on five firearms-related charges, including illegal transfer or possession of an assault weapon, according to court documents. The AK-47 that Donal Curtin III bought in Kentucky, a rifle with a 16.5-inch long barrel, came from Romania by way of gun importer Century International Arms Inc. Court records detail the weapon, and the fact that it was purchased at a dealer in Fort Campbell, KY, by Curtin III, who was living in Clarksville, TN at the time.

Police responding to calls from Curtin and his fiancee on the morning of July 7 found the rifle, wrapped in a navy blue blanket, along with other guns kept in a secured locker and another allegedly hidden by Curtin's fiancee in a motorcyle boot in the master bedroom of their Pond Street apartment. Thomas Drechsler, a Boston-based attorney, has denied his client's guilt. The Norfolk County District Attorney's office has said it will seek a special prosecutor to avoid the appearance of a conflict of interest.

According to Kentucky law, any U.S. citizen in that state "shall have the right to purchase or otherwise acquire rifles, shotguns, handguns, and any other firearms" allowed under state and federal law "from properly licensed dealers, manufacturers, importers, or collectors, and from unlicensed individual persons..." Century International Arms Inc. is a 50-year-old company that calls itself the largest North American importer of surplus firearms and accessories, according to its website. In addition to the AK-47, Century showcases a number of weapons, including the M60, an American machine gun introduced prior to the Vietnam War, and the Russian-made PK machine gun.

Curtin III bought the AK-47 last year at Fort Campbell, according to court documents, and sometime between then and July of 2011 gave it to his father, a 25-year veteran of the Braintree police force who has been for distinguished service.

The Curtins appear to have gone wrong, at least in part, according to the prosecution, when the son gave the AK-47 to his father without being a federally-licensed dealer, leading to charges for both men.

In a letter included in court documents from Lt. Kevin Ware to Braintree Police Chief Paul Frazier, Ware said that Curtin's possession of the weapon, with accessories such as a folding stock and pistol grip, likely violated a portion of Massachusetts law that carries a potential 10-year prison sentence, but that more research into the gun should be carried out. "We should, however, do our due diligence and make every effort to find out the manufacturing date of the weapon in question," Ware said, adding that tests by the state police shed no light on the date.