Supreme Court building. (J. Scott Applewhite/Associated Press)

One of the most buttoned-up institutions in the country will wrestle with the free-for-all culture of the house party as the Supreme Court hears a case set for Wednesday that began in a brick duplex in the District.

The weighty legal matters involve policing, arrests and searches in private homes.

But those issues are packaged in a case that includes a mystery hostess named Peaches, women in garter belts stuffed with cash and party guests who weren’t certain who owned the house they were in, but told police that “Peaches” was a renter who had invited at least some of them.

Attorneys on each side used “debauched” in their filings to describe the late-night bash on Anacostia Avenue a decade ago.

They split over whether D.C. police officers called to investigate noise complaints acted legally and reasonably when they arrested 21 people for trespassing — and whether the officers and the District government should have to pay upward of $1 million in damages a jury awarded most of the guests after charges eventually were dropped.

The outcome of the case may turn in part on how the justices view the loose etiquette of house parties and whether guests need to fully vet a host’s invitation. The night’s revelry, and how police handled it, already have sparked debate between two legal titans on opposing political ends of an important appeals court bench in Washington.

By the time police pulled up to the typically tranquil block in Northeast on March 16, 2008, the party was well underway, with lap dances, low lighting and the smell of marijuana.

Some guests and dancers told police they had been invited to a bachelor party. Others said it was a birthday party. Peaches, the purported host, was not there. When officers at the scene phoned the homeowner, he told them he hadn’t approved a party.

Sixteen of the partygoers filed suit after the charges were dropped, and a federal jury awarded $680,000 in damages that eventually reached nearly $1 million with legal costs added.

The city appealed to the U.S. Court of Appeals for the D.C. Circuit. A three-judge panel found that the officers were not immune from legal action for the unlawful arrests, leaving on the hook the city and two police officers — Andre Parker and Anthony Campanale.

The D.C. Circuit declined to rehear the case sitting with a full complement of judges. That decision prompted a robust dissent from conservative judge Brett M. Kavanaugh, who suggested that his colleagues were creating a new rule “divorced from the real world that police officers face” and a response from liberal judge Cornelia T.L. Pillard, who insisted that the court had done nothing to weaken protections for police.

At issue for the Supreme Court on Wednesday will be whether D.C. police were justified in making the arrests. And, even if the officers got it wrong and did not meet the “probable cause” standard, whether they should still be shielded from the lawsuit.

Government officials, including police officers, generally are protected from lawsuits when they carry out their duties in good faith.

The issues involving Peaches and the party house already appear to have divided the Supreme Court. The justices considered the case nine times before agreeing to add it to their calendar.

More than two dozen states — including Illinois, Maryland and Pennsylvania — and the Justice Department have lined up behind the District government. Attorneys general from 26 states contend that the D.C. Circuit ruling will have “vast consequences” for police nationwide because officers need to be able to judge whether suspects are telling the truth without being second-guessed.

On the side of the partygoers, the American Civil Liberties Union says reversing the ruling would make it harder for citizens to hold police accountable for violating constitutional rights — in this case, Fourth Amendment protections against unreasonable, warrantless searches of private homes.

It was after 1 a.m. when police entered the River Terrace house sparsely furnished with a few chairs and a mattress upstairs. Police arrested the partygoers only after hearing conflicting accounts about whether they had permission to be there, and about the absent host.

Reached by phone, “Peaches” told officers that the owner was fixing up the house for her to possibly rent and then she became evasive and refused to come to the party scene, according to police depositions.

After the arrests, at the 6th District police station, some officers debated the trespassing charges, court records show. After officers consulted with the attorney general’s office, charges were changed from “unlawful entry” — or trespassing — to “disorderly conduct.” At least one officer objected, explaining that suspects cannot be “disorderly” indoors, according to the officer’s deposition.

All of the charges eventually were dropped.

Despite agreement among lawyers on both sides about the broad outlines of what happened in those early morning hours, lawyers for the office of D.C. Attorney General Karl A. Racine and for the partygoers diverge over how police should have interpreted what they observed.

In the partygoers’ filing, attorney Nathaniel P. Garrett gives the justices a quick tutorial with a link to an article: “How the Kids Do It Now: Partying.” House party guests have no reason to ask whether the host is a renter or owner and may not even know the host, he wrote.

Officers knew only that the guests were “at a house party, engaging in common (albeit debauched) party activities, in a cheaply furnished home in a poor neighborhood, and that they neither owned nor rented the house themselves,” wrote Garrett, a San Francisco-based lawyer. “While this may be evidence of poor taste or poverty, or both, it is not evidence of knowing trespass.”

But to the city’s solicitor general, Todd S. Kim, it was an easy, reasonable call for police to make the arrests. The officers quickly determined that the partygoers had “no right to throw their unauthorized, debauched party in this unfurnished, unattended home,” he wrote.

“Since the partyers had used ‘Peaches’ to justify their presence, her evasive and untruthful behavior when questioned about it gave the officers reason to believe that she and the partyers had together fabricated” their story.

Years later, “Peaches” has not been unmasked in court documents and was never deposed as part of the lawsuit.

In siding with the partygoers, the D.C. Circuit said the officers did not meet the “probable cause” standard required for arrests because they had not considered that the partygoers thought they were welcome. Writing for the majority, Pillard said the partygoers believed — mistakenly, it turns out — that “Peaches” had permission to use the house for a party.

“It was undisputed that the arresting officers knew the plaintiffs had been invited to the house by a woman that they reasonably believed to be its lawful occupant,” Pillard wrote.

Kavanaugh and three other D.C. Circuit judges dissented and wanted the court to take another look.

People involved in criminal activity often assert their innocence to police, Kavanaugh wrote, and it was “entirely reasonable for the officers to have doubts about the partyers’ story and to conclude that there was probable cause to arrest.”

But even Kavanaugh acknowledged that the evening could have gone differently.

“Could [police] have broken up the party and then left? No doubt,” he wrote. “Indeed, in retrospect, that might well have been a better decision.”