The punishment: no more than 1½ years in prison, but perhaps no prison time at all.
Prosecutors in Coconino County, where the alleged attack occurred, say the disparity is unconstitutional. So in addition to bringing charges of kidnapping and assault against the 45-year-old man in the alleged attack in September, they have charged him under the standard rape law, setting the stage for a legal battle over whether Arizona's spousal rape statute violates the Constitution's equal-protection guarantees.
"The current statutes are extremely unfair and unconstitutional, and they need to be changed," said David Rozema, chief deputy in the Coconino County Attorney's Office.
Advocates for domestic violence victims say few states treat spousal rape and other forms of rape as disparately as Arizona does.
Under Arizona law, spousal rape is the lowest possible felony. The burden of proof is higher than it is in standard rape cases, and it makes no difference whether the spouses are estranged or living apart.
"It treats victims differently solely because of their marital status," said Keli Luther, of the Crime Victims Legal Assistance Project in Arizona. "We think this is really archaic."
About half the states treat spousal rape differently from other types of rape, according to the American Prosecutors Research Institute, the research arm of the National District Attorneys Association.
Some states give women less time to come forward with a claim against a husband or require proof that force was used. Most laws on nonspousal rape require proof only that the assailant lacked consent.
Tennessee says spousal rape should be punished by three to six years in prison, while other rapes carry eight to 12 years. In South Carolina, aggravated spousal rape involving couples living together carries a maximum of 10 years in prison; roughly the same crime committed by someone else can bring a penalty of 30 years.
Many spousal rape laws were drafted in the 1970s and were considered progressive at the time because they recognized it was possible to rape a spouse. Historically, wives were considered property of their husbands, and sex was regarded as a wife's duty.