The national office of the Sigma Pi fraternity has ordered its Boulder chapter to cease operations after five University of Colorado students told police they believe they were drugged while attending parties on the college town’s University Hill last month.

Boulder police are investigating an alleged assault that was reported at the Sigma Pi house, 1111 College Ave., on the same night the first two drugging victims were hospitalized. No arrests have been made in connection with the druggings, and when asked about that investigation Thursday, Boulder police spokeswoman Shannon Aulabaugh said, “Sigma Pi is not considered a suspect at this time.”

Because all the women had attended multiple parties, police said they couldn’t confirm where the students believed they were drugged.

But Jonathan Frost, executive director of the Tennessee-based Sigma Pi Fraternity and Foundation, said in an email Thursday that he was “aware of the reports and allegations” surrounding the Boulder chapter. He said the national office shut down the fraternity and launched an internal investigation, and is “fully cooperating” with CU officials.

“Sigma Pi has a zero-tolerance policy for illegal drug use and a zero-tolerance policy for any type of assault,” Frost wrote in an email to The Denver Post on Thursday after several requests for comment on the women’s allegations that they were drugged on the Hill. “Whenever any policy or law is broken by any member of Sigma Pi, we hold them responsible and respond accordingly, up to and including expulsion.”

Following publication of this story, Sigma Pi’s national office issued a news release expanding on Frost’s statement to The Post, saying the Boulder chapter has been “temporarily suspended” while the investigation proceeds. This means it cannot participate in or host any events, including chapter meetings, social events or recruitment activities. The Boulder chapter’s future will be determined following the conclusion of Sigma Pi’s own investigation, the fraternity said.

Ryan Huff, a spokesman for CU Boulder, said university officials hadn’t heard that the off-campus fraternity had been shut down.

“However, Sigma Pi national leaders have been in touch with Student Affairs officials and we’ve talked about recent alleged conduct and incidents,” Huff said.

“The ongoing investigation”

Five women came forward to the Boulder Police Department last month saying they believed they were drugged while partying on the Hill, the quintessential collegiate business and residential district popular with students that’s just across the street from the CU campus.

Since then, students have held a protest on campus as they clamor for answers about what happened to their classmates. Experts warn, though, that alcohol- and drug-related crimes — which can boil down to one person’s word against another’s — can be difficult to prove when evidence is hard to come by and memories are hazy.

On Oct. 18, Boulder police announced that two CU students had been hospitalized early that morning at Boulder Community Health after “unknowingly ingesting drugs while drinking alcoholic beverages at parties on University Hill.” Five days later, Aulabaugh said three more CU students came forward with similar allegations.

The Denver Post last week requested records from the Boulder Police Department for any calls to the Sigma Pi fraternity house over the past year, but that request initially was denied “due to the possible connection to the ongoing investigation,” according to an email from James Dann, administrative specialist with the department. After asking whether Boulder police could confirm that the Sigma Pi fraternity was under investigation, Aulabaugh last week said records related to that house could be released — but that Sigma Pi was not a suspect in any druggings at that time.

Yet Boulder police ultimately declined to release records involving an Oct. 18 response by officers to the Sigma Pi house on the Hill on a report of an alleged assault, saying the release of that information would be contrary to the public interest and “the integrity of an investigation and/or subsequent prosecution could be jeopardized.”

CU and fraternities sever ties

Fraternities at CU Boulder became independent of university oversight in 2004 after the alcohol-poisoning death of Chi Psi pledge Lynn “Gordie” Bailey Jr. After Bailey’s death, CU officials asked the fraternities to sign an agreement to delay rush until the spring each year, and ensure each chapter had a live-in supervisor. The fraternities declined, instead forming an independent, off-campus Interfraternity Council made up of 22 organizations.

But Sigma Pi was expelled from Boulder’s Interfraternity Council in 2013 after its members were accused of providing alcohol to potential recruits during the fall rush. The chapter’s parent organization didn’t revoke its charter at that time, meaning it had operated since then without any local oversight.

Last week, Mitchell Denny, a CU Boulder senior and president of the Boulder chapter of Sigma Pi, told The Denver Post that it was his job as president to “oversee the fraternity and the relations outside of the fraternity.”

When asked about the drugging allegations, Denny said he had reached out to the CU Police Department and was doing everything he could to deal with the situation.

“We are just trying to reach out to anyone that is willing to talk about any incidents or any reports or anything,” Denny said last week. “There has been a lot of rumors going around, and we are actively trying to search and sift through those rumors. I don’t really feel comfortable divulging a whole lot. I don’t have as much information as I’d like to, and neither do the police or the school.

“I’ve reached out to the girls to see their side of the story. They have not responded to me. A couple of them have, but they just are very quiet and just haven’t responded.”

When reached again Thursday, Denny referred The Denver Post to Frost, who leads the fraternity’s national organization.

Challenges in prosecution

Stan Garnett, who stepped down as Boulder County district attorney this year, said he wasn’t surprised when he heard students had reported to police that they believed they had been drugged while partying.

“It became clear during my time as DA that there were a lot of areas near the university that were centers for problems,” Garnett said. “One of them was fraternities and one was just general house parties.”

Garnett said he charged individuals with using drugs or alcohol to cause people to become incapacitated, but the DA’s office could never prove that an entire location was responsible.

“We never got an indictment for any case involving allegations that a particular party or particular house was a place where people were likely to be drugged,” Garnett said. “We never found a case where we felt we could prove sufficient evidence to meet the standards in a court of law where a particular location or fraternity house was engaging in a pattern of drugging people to have sex.”

Still, Garnett knew there were Boulder haunts that worried some students more than others. “You hear lots of rumors about places where, particularly young women, become unconscious very quickly,” he said.

But the presence of alcohol makes investigating these allegations difficult, Garnett said.

Janine D’Anniballe, director of Boulder organization Moving to End Sexual Assault, explained what often happens in cases where someone believes they were drugged while drinking.

“If someone feels like they’re drugged, and let’s say they are, and they’re woozy or out of it or incapacitated, by the time they wake up and figure out what might have happened and figure out what to do and where to go, the window has usually passed about testing this substance,” D’Anniballe said. “It’s so hard to test for because that window is so small.”

Signs that someone has been drugged while drinking include becoming incapacitated at a speed and intensity that doesn’t match with the number of drinks someone has had, having an “extreme” hangover that doesn’t seem fitting to the amount of alcohol consumed, and losing a sense of time and place.

“Again, someone can black out from a lot of alcohol, but that’s not typical if someone had two or three drinks,” D’Anniballe said. “If somebody had two beers and can’t remember the night before or wakes up with a hangover to beat all hangovers, that’s a sign that something else probably went down. I think taking action and doing it quickly is really the best somebody can do in that situation.”

“No one to keep them in check”

Alexandra Rice, a 20-year-old leader with the Boulder chapter of Christian sorority Alpha Delta Chi, is taking action on behalf of herself and her sisters. When asked how she felt going out after the alleged druggings, she said some of Boulder’s fraternities made her and her sorority sisters uneasy.

“We’ve had a lot of meetings recently where we’ve told our members to stay away from Sigma Pi because they’re unaffiliated,” Rice said. “Going to these fraternities is a lot more dangerous because there’s no one to keep them in check.”

In 2015, the IFC-affiliated fraternities even warned members of Boulder’s sororities to stay away from Sigma Pi and another unaffiliated fraternity, Kappa Sigma, because the two had been expelled for violations that “involved concerns for the safety and welfare” of members and guests.

Garnett acknowledged that most of the fraternities he and his team dealt with were “terrific and made up with young men who are responsible.”

He went on to add: “From a law enforcement perspective, you combine late adolescence with alcohol, and you’re going to have some fights, some DUIs and some allegations of sexual misconduct, and we had an obligation to look closely into this. The trick is to figure out how you do appropriate investigations without wasting everybody’s time and running the risk of falsely accusing someone.”

Marc Stine, who oversees the 22 fraternities in the Interfraternity Council, said Boulder’s fraternities have done a good job of acting responsibly. He said when students within the IFC’s fraternities are trying to sort out serious conflicts on their student-run judicial board, they often come up with more stringent sanctions for each other than Stine would suggest because they want to uphold their fraternities’ ideals and reputation. Stine also praised local law enforcement for stepping in when the allegations warranted.

“I was drugged on the Hill”

Olivia Lyda said she experienced her own version of hindered justice.

Lyda, a CU Boulder sophomore catching up on homework on campus, said some fraternity parties have left her feeling uncomfortable.

“Some aren’t a good scene,” Lyda said. “The guys have been gross, treating women like objects and just wanting to get laid and then tell their brothers about it. Some aren’t like that, though, but it does make it a lot less fun to go out.”

After praising the university for sending students emails letting them know when crimes happen and detailing tips on how to stay safe when going out, Lyda said in passing: “I mean, I get it because I was drugged on the Hill at a frat party. It was fine, though. My friends were there and took care of me, so I was actually really lucky.”

Lyda said she didn’t report her allegations because she didn’t want to falsely accuse anyone.

“This kind of thing happens more than people think, and then you wake up and are like, ‘What do I do?’ ” Lyda said.

D’Anniballe encourages anyone who thinks they have been drugged or sexually assaulted to call the Moving to End Sexual Assault 24-hour hotline at 303-443-7300 or call the police or show up at an emergency room.

“Women are entitled to go out and party with their friends and drink what they want, when they want, just as much as men,” D’Anniballe said. “The fact that we would ask women to curtail their behavior in a certain way to avoid these things is maddening.”

Updated Nov. 2 at 2 p.m. This story has been updated to include information from a statement released by Sigma Pi offering further information about its actions involving the fraternity’s Boulder chapter.