"It's certainly a concern we have -- that the women were targeted moreso than the men for possibly nefarious reasons," said Rosyln-Cle Elum Police Chief Scott Ferguson. "The majority of the people affected by the drugs were females."
The 12 were rushed to the hospital early today after they were given drinks spiked with a strong drug and then overdosed, police told ABC Seattle affiliate KOMO-TV.
One young woman remained in serious condition today at Kittitas Valley Community Hospital, officials said.
Police took one young man into custody after he was found having sex with a young woman, but he was later released after it was determined she was his girlfriend and over 18, KOMO reported.
Police said it appeared that none of the people who overdosed meant to get high or unconscious, because none had more than one or two drinks.
"We don't believe this was just a result of heavy drinking," Ferguson said.
"We don't know for certain [what drug was used]. We've drawn blood at the hospital," Ferguson said. "We're suspecting it's some type of roofie or some type of ecstasy, but that's yet to be known."
"Roofie" is the street name for flunitrazepam, a sedative commonly referred to as the "date rape" drug.
Some of the students who attended the party said they, too, believed that the drug involved was roofies.
Chris Unger, a Central Washington University freshman, told KOMO that people started falling unconscious soon after he arrived at the party.
"When I got there people started falling like flies," he said. "I carried about four people downstairs. ... We were pretty much worried about them passing out and stuff because they were not responsive -- they weren't doing anything."
He and other students at the party said they are convinced someone spiked the drinks with the date-rape drug.
"It was really scary," Katelynn Allen, a Central Washington University freshman who was at the party but said she did not drink, told KOMO.
"Everything was going fine, the music was playing, people were having fun -- and then all of a sudden all the girls were puking everywhere," she said. "Girls were outside on their backs."
Police became aware of the overdose problem late Friday night, after they were called at 11:10 p.m. about a possible overdose victim -- a young woman -- in a car at the Safeway grocery store in Cle Elum, Ferguson said.
The friends of the victim told police about the party and said that there were others there who also appeared to have suffered overdoses, he said.
When police got to the rented house in Roslyn, they found about 50 teens, many of them Central Washington University freshman, the chief said.
"As they entered the house they observed several individuals that appeared to be under the influence of some type of drug ... and were partially unconscious," Ferguson said.
Police questioned about 35 people at the scene of the party, but Ferguson said they have not yet determined who spiked the drinks.