JACKSONVILLE, Fla. -- The state attorney announced in a Tuesday morning news conference that due to a lack of evidence, no charges have been filed in a rape case involving a 15-year-old girl.

State Attorney Harry Shorstein said the case has been suspended.

For about eight weeks, detectives investigated allegations that a teenage girl was raped after an end-of-the-school-year party held on June 4 at a Neptune Beach oceanfront home. Neptune Beach police said at least 20 students, mostly from The Bolles School, attended the party in early June.

Police said the teenagers were drinking.

The girl, who was not a Bolles student, was found passed out facedown in the sand on the morning after the party. After coming to, she told police she was at the house party and after it moved to the beach she said she was attacked possibly by five people.

"The victim complained to fire and rescue and police initially that she had received and was experiencing severe abdominal pain. The rescue report indicates that the patient stated that she consumed a large amount of alcohol and that there was a possible sexual assault," Shorstein said.

The 15-year-old was taken to an emergency room and was later examined.

"An expert in pediatrician, gynecological, sexual assault examinations ... performed a complete examination of the child and could neither confirm nor negate allegations of sexual abuse or assault. She determined that there was no physical evidence of vaginal or oral penetration," Shorstein said.

The state attorney said that could not be used to determine that no sexual assault -- vaginal or oral -- occurred.

As the investigation of what happened after the party began, police said the investigation was being hampered by the parents of partygoers who refused to allow their teens to be interviewed. But Shorstein said that as the investigation proceeded, 47 witnesses were either interviewed or had sworn statements taken.

Of the 47 witnesses, the state attorney said 44 are children. Five witnesses were subpoenaed, including the parents who had the party, their daughter and two of the other witnesses.

During the news conference, Shorstein also spoke about DNA evidence in the case.

Two weeks ago, the Florida Department of Law Enforcement turned over the results of its analysis of evidence from the incident to the Neptune Beach Police Department and the state attorney's office, allowing the agencies to move forward in their investigations.

"The DNA evidence suggested some contact between the 15-year-old child and the potential suspect, but that contact could be consistent with vaginal contact, could be consistent with oral contact or could be consistent with non-sexual contact," Shorstein said. "DNA swabs were taken from the child's vaginal area and from the child's mouth. No DNA -- foreign DNA -- was determined to exist from the child. In addition, there was not evidence of semen in or on the child's body."

The state attorney attributed investigators' inability to resurrect exactly what happened to partygoers' significant alcohol consumption the night of the party.

"We do believe the child suffered a traumatic event ... and has been honest and sincere with all of us in law enforcement since the night of the incident," Shorstein said.

The consumption of alcohol by minors has been a high-priority issue with the state attorney's office.

"It is the duty and responsibility of us in law enforcement to base our decisions on the existence of admissible evidence. At this time, there is not the existence of admissible evidence that would allow prosecution of any kind, including prosecution of adults who may have wrongly allowed the consumption of alcohol," Shorstein said.

"Every child that we interviewed, and when I say child I'm talking about 16, 17 and 18 year olds, at that party, indicated that they never saw the parents downstairs, that they never displayed alcohol to the parents in any kind of way. The parents indicated to us that they knew there were going to be several kids invited over, that they thought it maybe would be 10-15 people that they specifically told their children at the party that there would be no alcohol and then trusted that their children would follow their orders," said assistant state attorney Julie Schlax.

Girl's Father Reacts To State Attorney's Decision

While no criminal action is being taken, that may not stop the family of the 15-year-old girl from suing.

"So if I am a parent and I am off in some room and the kids are running around the house drinking and I am saying I did not know what they are doing, there is a potential, some claim, that they are asserting ignorance in a deliberate fashion but in fact they had such knowledge," said federal prosecutor Curtis Fallgatter.

It would take a court to decide if the parents knew what was going on at the party.

In a conversation with Channel 4, the 15-year-old's father said he is not happy with the decision to suspend the investigation.

"We thought we had hit the jackpot, or at least I did as her dad, when they found my daughter's DNA inside that boy's underwear," the father said. "The detectives that I've spoken with and the state attorney's assistant, who have been handling this case, told me that they 100 percent believe my daughter. I've had all kinds of thoughts go through this as far as wondering, 'Could it possibly be that she was so intoxicated -- do a lot of girls get intoxicated and claim rape?' I was told no, that doesn't really happen unless there was something. It's not a prominent occurrence. I know her, and why would she?"

He said he is not going to drop the case and will if necessary pursue a civil action.

Channel 4's Jim Piggott also talked with attorney Hank Coxe, who represents the 17-year-old potential suspect in the case. Coxe said his client talked to police on Thursday for three hours and passed a polygraph test.

Coxe told Channel 4 that as far as he is concerned the case is over. He also said he had concerns about the case being labeled as a gang rape.

"It is a shame that so many high school students were branded with those initial reports that they would have been anywhere near a gang rape. I thought it was so unfair to every one of them, and unfair to all the kids from that high school who weren't there but were probably being questioned, 'Were you there? Were you there?' It's so unfair," Coxe said.

The rape case has been suspended, meaning if some evidence comes forward in the future, the case could be resumed. There is a minimum three-year statute of limitations on the rape allegation.