The Associated Press

BILLINGS — Police officers did not illegally arrest a woman for drunken driving hours after they let her go for riding a horse while intoxicated on a Billings street, the Montana Supreme Court said in dismissing the woman’s case.

Two Billings police officers responding to a report of a drunken rider on South 36th Street near downtown Billings came across Dawnalee Ellis-Peterson just after 7 a.m. on April 29, 2013.

Ellis-Peterson, who was 43 at the time, was trying to get back on the horse, and she told the officers with slurred speech that she would just walk with the horse, according to Assistant Attorney General Tammy Plubell.

The officers let Ellis-Peterson go because she was on foot, but then went to her house later that morning after she called 911 to complain that she should be allowed to ride her horse without being pulled over.

“Ellis-Peterson told the officers she was okay, wanted to be left alone, and was ‘just drunk,’” Plubell wrote in her argument filed with the court. Ellis-Peterson stood nude in the doorway and yelled incoherently at the officers as they were leaving, Plubell added.

The officers asked a neighbor to call police if she saw Ellis-Peterson leave in her vehicle. Shortly after they left, Ellis-Peterson drove off in a pickup truck, and the neighbor called 911, Plubell wrote.

One of the officers pulled Ellis-Peterson over in a parking lot and informed her that she was being arrested for suspicion of driving under the influence.

Ellis-Peterson’s attorney, Benjamin LaBeau, doesn’t dispute the police’s general narrative of events, but argued in District Court and to the Montana Supreme Court that the officer did not have probable cause to arrest Ellis-Peterson.

The officer did not require her to perform any field-sobriety tests, and only relied on his previous encounters with her to support his decision.

“The officers state Ellis-Peterson is intoxicated, but have very little to base their statements beyond conjecture and speculation,” LaBeau wrote in his argument to the high court.

The district judge denied LaBeau’s request to suppress evidence taken after the arrest, and Ellis-Peterson reached a plea deal with prosecutors that resulted in a 13-month sentence with the Montana Department of Corrections on a DUI charge.

Ellis-Peterson appealed the judge’s denial of the motion to suppress the evidence, contending the arrest was illegal.

Justice Patricia Cotter, who wrote the unanimous Supreme Court opinion on Monday, said the officer had probable cause to arrest Ellis-Peterson based on their previous encounters, and sobriety testing is not a prerequisite for probable cause.

“During their second interaction, a mere 20 minutes before her arrest, she even told Officers Beck and Edwards that she was drunk,” Cotter wrote.