Thom LeDoux, the district attorney for the state's 11th Judicial District, said investigators did not find aggravating factors like adults' involvement, the posting of graphic images to the Internet, coercion, and related unlawful sexual contact.
He added that while the "decision does not condone or excuse the behavior of the individuals involved," authorities wanted to avoid "the inequities in punishing just those that have come forward, have been identified, or have cooperated with the authorities."
Moreover, he expressed hope that students and parents will learn from the ordeal. He noted presentations this week to high school and middle school students in Cañon City, about 115 miles south of Denver, as proof of educators' and law enforcement's efforts to drive those points home.
Still, those who don't heed these lessons -- and are found to still possess "any illegal materials of this nature, associated with this situation or otherwise" -- could face charges. Parents of those students implicated in the scandal will receive "warning" letters noting their children's alleged involvement.
"In other words, we expect and demand that the children of our community comply with the laws of this state, particularly in this area moving forward," LeDoux said.
As the district attorney pointed out, the lack of charges doesn't mean the implicated students won't be punished by the school district. Cañon City High School already canceled one of its football games after "a large number" of players were implicated.
The school district said it also suspended an undisclosed number of students after the scandal was publicized in November.
LeDoux revealed Wednesday that middle school students were also allegedly involved in sexting.
In Cañon City, hundreds of students' body parts were photographed and shared in the secret phone-apps, and Schools Superintendent George Welsh said that "there isn't a school in the United States" that hasn't dealt with students sexting.
Some of the nude photos were believed to have been taken on the high school campus, Welsh said last month.
Students used a photo vault app that hides the nude photos by appearing to be a calculator or media player, Welsh said. A password is required to access the photo vault.
The offenses could have carried serious felony charges for the youths.
That's because Colorado is one of 30 states without modern-day sexting laws, which often provide leniency to adolescents as long as the sexting is consensual and is considered a misdemeanor mistake in exploring sexuality.
Instead, Colorado and 29 other states rely on long-standing child pornography laws that could ultimately put a minors on a sex offender registry, experts say.
The result is that underage sexting in America can have vastly different legal implications depending on the state in which it occurs.
At one end, some states rely on child porn laws originally intended to prosecute adults preying on children. Those laws are now sometimes used against sexting teenagers and can carry heavy penalties: felony imprisonment with sex offender registration.
At the other end are new laws providing informal punishments to underage youths such as counseling, community service, and Internet safety education, perhaps without any juvenile record of the misdemeanor offense as long as coercion, blackmailing and other serious offenses aren't involved, experts say.
"What we learned in Colorado is a perfect cautionary tale of why it should be put into the books," Florida Atlantic University's criminology professor Sameer Hinduja said of adolescent sexting.
"If nothing else, what happens in Colorado should enforce a conversation across the nation in dealing with this phenomenon with kids," said Hinduja, who advocates keeping youth offenders out of the criminal justice system and instead using informal penalties such as community service and fines.
Of the 20 states with sexting laws, 11 of them classify the offense as a misdemeanor, prescribing out-of-court "diversion" remedies or informal sanctions such as counseling, according to the Cyberbullying Research Center
run by Hinduja and criminal justice professor Justin W. Patchin of University of Wisconsin-Eau Claire.
Four of the 20 states, however, also allow for felony charges.
Florida and Utah, for example, allow for a felony charge for repeat offenders. Georgia law says the charge depends on the facts of the case.
The fourth state, Nebraska, is the only state among the 20 that makes all sexting offenses a felony, but grants an affirmative defense to those age 18 and younger if the sexting was with another minor at least age 15 and was consensual, without distribution to another to another person.
Even with all the new laws, most of the country remains far behind the fast-moving pace of teens and technology, analysts say.
"Since they don't have these teen sexting laws, there are draconian measures to deal with these children" in 30 states, including Colorado, CNN legal analyst Joey Jackson said.
"But the reality is kids do what they do. So should there be statutes on the books that are going to throw the book at the kid?... In essence, make them felons?" Jackson said.
Jackson and other experts prefer putting teenage offenders through "the juvenile (rehabilitation) route, so that the draconian measures don't really apply to these (students) who I'm sure are just generally good, wonderful kids, but they're just acting like kids and now deemed to be criminal," he said.
The other 20 states with modern-day sexting laws are Arizona, Arkansas, Connecticut, Florida, Georgia, Hawaii, Illinois, Louisiana, Nebraska, Nevada, New Jersey, New York, North Dakota, Pennsylvania, Rhode Island, South Dakota, Texas, Utah, Vermont and West Virginia.