Where do you draw the line between public and private spaces? Is being drunk on your personal front steps less of a public nuisance than if you were drunk on the stoop of an apartment building where you live with others? For the highest court in Iowa, the answer is yes.

This morning, the Iowa Supreme Court reversed the conviction of a woman arrested in 2013 for public intoxication outside of her own home, ruling [PDF] that she “cannot be guilty of public intoxication because she was not intoxicated in a public place.”

Before she was arrested, it was the woman who called 9-1-1 claiming she was the victim of domestic violence.

When police arrived, she was inside the house and stepped outside to speak with the officer on her front steps because she didn’t want to upset her kids.

Meanwhile, the alleged aggressor told the other officer that the dispute had been over his car keys. He claimed he was trying to prevent her from driving because she was drunk and didn’t have a driver’s license. The woman then punched him in the eye, he said, admitting that he did grab her arm in an effort to prevent her from hitting him again.

Police then gave the woman a breathalyzer test and found that her blood alcohol concentration was .267, far above any standard for being drunk. As a result, she was arrested for public intoxication. Because this was a repeat offense, the level of the charge was bumped up to a serious misdemeanor.

During the trial, prosecutors pointed out that the woman’s steps don’t in anyway constitute a front porch — no roof, no awning, no enclosures of any kind — and the front yard was not separated from the public sidewalk by a fence or any similar physical divider; not even a “keep off yard” sign.

The woman countered that the lack of a fence or roof didn’t make her steps a public space. Besides, she was drunk in the privacy of her own house until the police came and she stepped outside to talk to them.

But the trial court sided with the prosecutors, saying her steps were plainly accessible and visible to any passersby. Thus, according to the lower court, any member of the public had an implied invitation to use the front stairs to communicate with the woman.

In reviewing the appeal, the Iowa Supremes noted that they made a decision 12 years ago stating that apartment hallways and front steps were “public spaces” but that they had explicitly left unresolved this matter with regard to single-family dwellings.

In that earlier ruling, the court had stated that apartment building tenants are “entitled to be free from nuisance and annoyance and to be protected from the actions of a fellow tenant.” So, even though the public at large might not have access to an apartment building, co-tenants in an apartment complex constitute “the public” when they use common stairways and hallways.

But, noted the court, “the front steps of a single-family home are an access point, whereas the front steps of an apartment house are a thoroughfare,” and “a single individual or family may bar access to the front steps of a single-family home, [but] no single tenant holds the right to bar access to the apartment house.”

And even though friends, neighbors, postal carriers, delivery people, and certain others might have an implied license to access the front steps of a single-family dwelling, the court says “there is a significant difference between the implied invitation extended to a prospective customer of a business and the implied invitation allowing people to approach the front stairs of a single-family residence. The difference is the expectation of the person or enterprise deemed to have extended the invitation. A business generally wants as many people as possible to accept the invitation; we doubt the same is true for most inhabitants of single-family homes.”

The court did acknowledge that there are situations in which the line between private front yards and public spaces is blurred.

“For example, residents of a single-family home could decide to hold a yard sale and post signs around the neighborhood advertising the day and time it will take place,” writes the court. “Similarly, homeowners aiming to sell their property could host and advertise an open house, inviting any person to visit for a tour.”

But since none of those examples apply to the case involved in this appeal, the court concluded that her front steps were a private space.

“[I]f the front stairs of a single-family residence are always a public place, it would be a crime to sit there calmly on a breezy summer day and sip a mojito, celebrate a professional achievement with a mixed drink of choice, or even baste meat on the grill with a bourbon-infused barbeque sauce—unless one first obtained a liquor license,” concludes the court. “Additionally… any intoxicated person who responsibly secures a ride home from a sober designated driver could be arrested for and convicted of public intoxication because they traversed the stairs of their single-family house while intoxicated.”

The court reversed the conviction and remanded the case to the lower court for dismissal.

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