Denver Judge Ben Lindsey becomes an early advocate for juvenile justice, establishing a juvenile court system based on Chicago's model, established just four years earlier. Over the next decade, Lindsey emerges as a national leader in the juvenile justice movement.

The United Nations adopts the Declaration on the Rights of the Child, which recognizes that children need special legal protections because of their immaturity. The United States ratifies.

Colorado defendants aged 16 and over are made eligible to be tried as adults on Class 1 and 2 felonies, but only after a hearing before a juvenile court judge.

Colorado drops to 14 the age at which juveniles may be tried as adults for Class 1 felonies, at district attorneys' discretion.

The United Nations adopts the International Covenant on Civil and Political Rights, which requires that members emphasize rehabilitation over punishment for juvenile offenders.

Colorado extends the minimum term before parole eligibility for inmates sentenced to life in prison from 10 years to 20 years.

Colorado defendants as young as age 12 can now be tried as adults for Class 1 and 2 felonies, at district attorneys' discretion.

Colorado extends the minimum term before parole eligibility for inmates sentenced to life in prison from 20 years to 40 years.

The United Nations adopts the Convention on the Rights of the Child, banning sentencing juveniles to life without parole. Of the 140 signatory nations, only the United States and Somalia fail to ratify it.

The minimum term for Colorado inmates sentenced to life in prison is extended from 40 years to the inmate's natural life, meaning life without parole.

The United States ratifies the International Covenant on Civil and Political Rights but attaches a reservation that "the United States reserves the right, in extreme cases, to treat juveniles as adults."

Colorado passes a Victims' Rights Amendment to the state constitution requiring that a victim's family be notified and have the option of attending a hearing in the event of any change in an inmate's sentence.

On Nov. 4, Colo. State Policeman Lyle Wohlers is murdered by juveniles Marcus Fernandez and T.J. White. The case becomes a notorious example of teen violence.

On Dec. 17, Jacob Ind, 15, kills his mother, Pamela Jordan, and his stepfather, Kermode Jordan, with help from 17-year-old Gabrial Adams.

A string of violent crimes across the country, many committed by juveniles, lead some in the media to label the summer of 1993 the "summer of violence." On Sept. 7, Colo. Gov. Roy Romer calls for a special legislative session and a 3-year study of the problem. That study recommends an overhaul of the state's Children's Code covering juvenile offenders.

In People v. Fernandez, the Colorado Court of Appeals rules that sentencing juveniles to life without parole is not cruel and unusual punishment.

In May, Jacob Ind's murder trial begins. He is convicted of two counts of first-degree murder and is sentenced to life without parole, the mandatory sentence for that charge. The judge in the case, Jane Looney, speaks out against the mandatory sentence.

In December, Ind's accomplice, Gabrial Adams, is also sentenced to life without parole after a separate trial.

Jacob Ind's appeal is rejected. That year, 152 juveniles are sentenced to life without parole nationwide, the most in any calendar year.

The U.S. Ninth Circuit Court of Appeals, in Wright v. Harris, upholds sentencing juveniles to life without parole, ruling that the youth of the defendant has no obvious bearing when assessing the proportionality of a punishment.

On Nov. 21, Trevor Jones, 17, shoots and kills Matt Foley as Foley attempts to buy a gun from him.

In June, Trevor Jones is sentenced to life without parole under Colorado's felony murder law. Even though the jury determines that the shooting was accidental and convicts him of manslaughter, Jones is eligible for the mandatory sentence under the state's felony murder statute because the death occurred during the commission of a robbery.

The Colorado legislature revises the state's criminal code for juveniles. The changes give prosecutors broader discretion to file charges against juveniles directly in adult court, bypassing a hearing in juvenile court.

The MacArthur Foundation Research Network on Adolescent Development and Juvenile Justice publishes research on juvenile brain development showing that juveniles are less culpable for their crimes and less competent to stand trial by reason of adolescence.

On June 5, Nathan Ybanez, 16, murders his mother, Julie. His friend Erik Jensen, 17, is present at the apartment and helps Nathan clean up afterwards. A third teen, Brett Baker, also helps clean up and later testifies against Erik and Nathan in exchange for prosecutors dropping charges against him.

On April 20, Eric Harris and Dylan Klebold go on a rampage through Columbine High School in Littleton, Colo., killing 13 and wounding 24 before taking their own lives.

On July 15, Kris Lohrmeyer, 17, is killed in a carjacking in Colorado Springs. Police arrest three suspects, two of whom plead to second-degree murder in exchange for implicating the third, 15-year-old Andrew Medina.

In August, months after the Columbine massacre, Erik Jensen's trial begins. It lasts one week, and he is sentenced to life without parole.

In October, Nathan Ybanez's trial begins. His lawyer calls no witnesses, and two days later Ybanez is sentenced to life without parole.

In May, Andrew Medina's trial begins. Medina's original public defender, affiliated with the same church as the victim's family, has Medina write them a letter of apology. The letter is used against Medina in court. Medina is found guilty, and he is sentenced to life without parole.

On July 26, Alison Parker of Human Rights Watch interviews Andrew Medina in Colorado's supermax facility, where he had been kept in solitary confinement since 2002. Prison authorities say Medina was sent to the supermax for gang activities while in prison.

The Colorado State House

In February, Human Rights Watch and Amnesty International publish a report on the 2,225 U.S. inmates serving life without parole for crimes they committed as juveniles.

In March, the U.S. Supreme Court, in Roper v. Simmons, rules 5-4 that sentencing juveniles to death violates the Eighth Amendment prohibition against cruel and unusual punishment. The Court notes that juveniles lack the "well-formed" identities of adults and are susceptible to immature and irresponsible behavior, and that juveniles are "categorically less culpable" than adult criminals.

In May, Colo. Gov. Bill Owens vetoes a bill sponsored by State Rep. Lynn Hefley that would have banned sentencing juveniles to life without parole.

In September, the Rocky Mountain News begins a four-part series on juveniles serving life without parole, including Jacob Ind.

In February, the Denver Post launches its own four-part series on teens serving adult sentences. It covers the cases of Nathan Ybanez, Erik Jensen and Trevor Jones.

On April 27, the Colorado General Assembly passes a law allowing juveniles sentenced to life in prison to be eligible for parole after 40 years. In a concession to district attorneys and victims' advocates, however, the law is not made retroactive. As a result, 45 Colorado inmates are still serving life without parole for crimes they committed as juveniles.