Of 182 boys and young men recently locked up in Illinois' three medium-security youth prisons, at least 135 used to miss so much school that they were labeled chronic truants.
Nearly 60 percent couldn't even read at the third-grade level when they were booked in.
At the largest of the three facilities, the Illinois Youth Center St. Charles, all but nine of the 72 youths had dropped out of school entirely by the time they were incarcerated.
These figures, calculated by the Tribune from newly obtained state prison data, serve as a grim reminder that absence from school in the early grades is often the first warning of criminal misconduct that can destroy young lives as well as burden society with the costs of street violence, welfare and prison.
The records underscore the stark consequences of a crisis in K-8 grade truancy and absenteeism in Chicago that officials long ignored but have promised to address in the wake of a Tribune investigation that found tens of thousands of city elementary students miss a month or more of school in a year.
The prison data consist of raw numbers, but behind them is a ragged parade of youths whose cases fill the docket in Cook County Juvenile Court.
One 2011 court report noted that a 15-year-old boy accused of selling $10 and $20 bags of heroin from an abandoned South Side building "is not attending any school at this moment." In fact, he had disappeared from Chicago's public schools two years earlier, court records show.
Officials who run Illinois' juvenile prisons say there are many others just like him.
"When they are not coming to school, they are getting themselves in trouble," said Kye Gaffey, superintendent of the juvenile prison schools. "We have youth who've reported to us that they haven't been in school since the fourth grade."
Under Illinois law, students cannot legally drop out of school before age 17, but hundreds do in Chicago every year, though sharp inconsistencies in the district's year-to-year attendance data make it difficult to know how many.
From 1999 through 2007, for example, roughly 3,000 students a year in grades K-8 were officially listed as dropouts. The number spiked to 6,625 in 2008, when Chicago included kids who were supposed to transfer to another school but never completed enrollment there.
After that, Chicago officials say, a state rule change meant they no longer had to report dropouts in the elementary grades. Still, the Tribune's analysis of the district's internal attendance database found that thousands of kindergartners through eighth-graders were listed as "unable to locate" or "did not arrive" in the three school years from 2008-09 to 2010-11.
"We know that we have a population of thousands of children who are disengaged from school and who need additional supports to get them re-engaged, back in the classroom, away from possible negative influences and working toward academic achievement," said district spokeswoman Robyn Ziegler.
In juvenile court, the Tribune examined scores of cases in which children had all but disappeared from class before reaching high school, even if they were not officially listed as dropouts.
One 14-year-old who was arrested for aggravated assault and theft in 2011 had withdrawn from school a year earlier, in seventh grade, when he was threatened by gang members and "is not able to return there due to safety issues," a court report said.
Another boy the same age who lived in a West Side crack house and sold heroin rarely attended school and "could barely write his name," according to a court evaluation.
Detached from school long before the legal dropout age, many of these youths became foot soldiers in the violent gangs that have terrorized Chicago's poorest neighborhoods and roiled the politics of City Hall.
"We are all aware of the tremendous impact truancy has had on the school kids of Chicago. It is not surprising that so many of them end up here," said Cook County Circuit Judge Michael Toomin, presiding judge of the Juvenile Justice Division.
Many absent grade schoolers came from single-parent households racked by intense poverty, substance abuse or mental illness, juvenile court records show. Some youths switched schools every year as their families fled foreclosure and debt, while the elementary schools in their South Side and West Side neighborhoods had few resources to retrieve missing students or even connect with their relatives.
Court officials could barely find school records for one 15-year-old accused of selling foil packs of heroin on a West Side street corner in 2011; the boy had not been enrolled for two years, and school officials said "he was not in the system," a court report said.
Born to a mother who died of a drug overdose and a father who was killed in a drive-by gang shooting, the teen was being raised by a grandmother weakened by several strokes. While missing from school, he had been arrested five times in the previous 13 months on drug and robbery charges, and admitted to court officials that he smoked three marijuana "blunts" a day.
Another West Side 15-year-old arrested nearby with 32 small plastic packets of heroin illustrates the intense challenges chronic truants present when they do attend school.
When that seventh-grader was in class, he used the school computer to troll gun websites or slept "at his desk or (on the) floor during class and disrupts the class with his snoring," a teacher reported. "The minor refuses to wake up after being requested multiple times."
Experts say the challenges of getting such youths on track increase every year they detach more completely from school, especially if their parents aren't involved or accountable for their absences.
Consider a 15-year-old boy brought into juvenile court after he snatched a young woman's iPhone in 2011. Court records described a "non-reader" who "has not attended school for approximately two years." He had been detained by police at least 17 times for robbery, mob action, assault and other street crimes, records show.
Even so, Cook County probation officials persuaded a high school to enroll the teenager, but he and his mother never completed the registration paperwork, and authorities eventually gave up.
"The table has been set for them, but for some reason, they refuse to take a seat," said a report to the court. "With the family's lack of follow-through with the services that have been put in place, it's felt that the probation officer's efforts are in vain."
It is common wisdom that school is the best place for a child to be in the long run, said Loyola University Chicago criminal justice professor David Olson. But many of the youths and families that pass through juvenile court live in such desperate conditions that they're not able or willing to think about the distant future.
"They think about what's going to happen today, and 'if there's a chance I'm going to get beat up (at school) today, I ain't going,'" Olson said. "'And if the school threatens me with detention if I'm absent, then I'm not going tomorrow either, because I don't want to serve detention.'
"With the 14-year-old selling heroin, I don't know if the system has the capacity or the resources to do enough. They're already so far down a road of criminal behavior that it may be difficult to correct it," Olson added. "You read some of those cases, and you're like, my God, even when they were 3 years old they didn't have a shot."
Illinois has just over 800 students in its eight state youth prisons. The average young inmate enters scoring between the fifth- and sixth-grade level in reading, and Gaffey said school records and the teens' own stories suggest that elementary-grade truancy is increasing across the state amid rising rates of child poverty and homelessness.
"But even if the youth reads at the third-grade level, that doesn't mean they're cognitively at that level," Gaffey added. Many have talent, tenacity and broad life experiences, and typically they can communicate verbally "within the high school level."
The Tribune also analyzed math and reading scores for the 42 adult inmates enrolled in the Big Muddy River state prison's literacy program and found the average inmate started at the sixth-grade level, with seven of them testing at third grade or below.
"If I had connected to school, my life would have gone different in thousands of ways," said 41-year-old Big Muddy inmate Robert Sloan, interviewed in September as part of the Tribune's truancy investigation.
Sloan, who has spent much of his adult life incarcerated for methamphetamine dealing and sexual assault convictions, is now struggling to improve on his fourth-grade math and reading scores.
"You feel like a fool when you don't know how to fill out (a job) application. You say, 'I don't want this stinking job.' But you are thinking, 'I wish I was smart enough to read the application,'" Sloan said.
"I always blame the drugs, but it was me not having an education that was the biggest step, because I always fell back on drugs when I felt stupid," he said.
Program coordinator Sherry Bowling said more than 100 inmates are on the waiting list to get into Big Muddy's remedial reading and math classes. Tutoring hundreds of inmates over the years has taught her one basic lesson, she said: "The lower the level of education, the higher the likelihood of them being incarcerated."