Feb. 18, 2008 -- Before going on a shooting rampage at Northern Illinois University, Steven Kazmierczak left a Valentine's Day note for his girlfriend.
"Jessica you're the best! You've done so much for me, and I truly do love you. You will make an excellent psychologist, or social worker someday! Don't forget about me! Love, Steven Kazmierczak," the love note read, offering only the slightest hint that he would kill five people and then himself later that day.
Jessica Baty, who was Kazmierczak's valentine, told CNN, "I still love him."
"I can't believe he is gone. I can't believe he took other people with him. That wasn't the Steve I knew. He was anything but a monster, he was the nicest and most caring person ever," Baty said, with tears streaming down her face.
It was the latest in a confusing portrait of the mild-mannered, award-winning graduate student who was also an Army reject who needed medicine to contain his anger and violent urges.
A new photo of Kazmierczack also revealed a large color tattoo on his forearm of a doll from the popular horror movie "Saw" driving through a pool of blood on a tricycle.
This weekend the manager of the mental treatment center for teens where Kazmierczak lived for a year, guessed the shootings were fueled by his being off medication.
"He didn't like to take his meds. He was kind of quiet, kept to himself," said Louise Gbadmashi, a former manager at the Thresholds-Mary Hill House in a phone interview.
"It's hard to tell when he's violent because his expression doesn't change," said Gbadmashi, who also recalled Kazmierczak cutting himself.
After high school, Kazmierczak's parents had sent him to Thresholds-Mary Hill House, a psychiatric treatment center for teens, to get therapy and medication for what was described as "unruly" behavior.
"He never wanted to identify with being mentally ill," she said. "That was part of the problem."
Apparently, in recent weeks Kazmierczak's problems were re-emerging.
"We have spoke to people who are close to him and apparently he had been taking medication. He had stopped taking those medications and had become somewhat erratic in the last couple of weeks," said NIU Police Chief Donald Grady.
The chief declined to specify the type of medication the gunman was on.
Police discovered other clues on Saturday in a Travellodge hotel room near campus where Kazmierczak stayed only three days before the deadly shooting spree. He checked in paying cash and signing in using only his first name, the hotel manager Jay Patel said.
According to Patel, he Kazmierczak left cigarette butts, empty energy drink bottles and cold medicine containers scattered around the room.
Police also found a duffel bag with its zippers glued shut that a bomb squad unit safely opened, only to find more ammunition.
In an erie twist, Kazmierczak purchased the ammunition from the same website as the Virgina Tech shooter.
In September, 2001, Kazmierczak joined the Army. Six months later he was issued an administrative discharge before he completed basic training, a defense official told ABC News.
The Privacy Act forbids the Army from characterizing the reason for Kazmierczak's discharge.
Kazmierczak had most recently been studying mental health issues at the University of Illinois, and had taken a job as a guard at a prison, according to his academic adviser.
But his career as a correction officer at the Rockville County Correctional Facility was short-lived, according to Doug Garrison, a spokesman for the Indiana Department of Correction.
"[Kazmierczak] was employed, starting the 24th of September 2007, as a correction officer at the Rockville Correctional Facility," Garrison told ABCNEWS.com. "He left employment on the 9th of October 2007."
"He just did not come back to work," said Garrison.
Those Who Knew Him
Kazmierczak's sister, Susan, posted a statement on the door of her Urbana, Ill., home that said: "We are both shocked and saddened. In addition to the loss of innocent lives, Steven was a member of our family. We are grieving his loss as well as the loss of life resulting from his actions."
"Steve was the most gentle, quiet guy in the world. ... He had a passion for helping people," said Jim Thomas, an emeritus professor of sociology and criminology at Northern Illinois who taught Kazmierczak, promoted him to a teacher's aide and became his friend.
"He was very intelligent, brilliant really," said Alexandra Chapman, a graduate student at NIU who tutored with Kazmierczak and knew him well.
On a music site message board from 2006, posters who claimed to be his co-workers wrote, "I remember Steve Kazmierczak … the kind of person who injured kids on the train ride cuz he was mental and he shouldn't be given domain over kids on little faux-train cars with an aluminum baseball bat … "
Police Chief Grady said that those who knew him "revered him as an outstanding student" and had no inclination that Kazmierczak was capable of such carnage.
"I just want people to know he didn't fit the profile. He did a very terrible thing and there is no way we could have foreseen that at all," said Chapman.
Kazmierczak had served as a member of the NIU Academic Criminal Justice Association, was a teaching aid during his undergraduate years and in 2006 even received a Dean's Award from the sociology department.
In 2006, Kazmierczak was a co-author of an essay entitled "Self-Injury in Correctional Settings: 'Pathology' of Prisons or of Prisoners," in which an attached biography described him as having just begun his graduate work at NIU.
Kazmierczak's interests are listed as corrections, political violence and peace and social justice, according to the essay, and he had plans to co-author a manuscript on the role of religion in the formation of early prisons.
In another biography, apparently written by Kazmierczak for the Academic Criminal Justice Association's Web site, he pledged his commitment to social justice and his academic work.
"I've worked very hard as a student," the entry reads.
Former Professor Remembers
"It was very difficult and overwhelming to hear the news," said Jan Carter-Black, an associate professor of sociology, who was both Kazmierczak's professor and adviser at the School of Social Work at the University of Illinois. "I found Stephen to be a very committed student -- extremely respectful of me. I enjoyed having him as a student."
Kazmierczak was a student of Carter-Black's for about a month in the fall of 2007, when he was enrolled in a class called Human Behavior and the Social Environment.
The course, said Carter-Black, focused on the connection between human behavior and the surrounding environment, and met once a week for three-hour sessions. Each class contained around 30 students, and Carter-Black said Kazmierczak always interacted with his peers well during group work, and participated regularly in class discussions.
Toward the end of September, Kazmierczak withdrew from Carter-Black's course to take a job in the prison system, and became a part-time student. In January 2008, Kazmierczak returned to full-time status.
Despite advising him on his courses on mental health issues, Carter-Black said she never noticed anything out of the ordinary about Kazmierczak, and added that he "looked like all the other students."
Carter-Black said she had no knowledge of Kazmierczak's medical history or treatment.
Kazmierczak grew up in Elk Grove Village, a suburb of Chicago, Ill. He was a 'B' student at Elk Grove High School, where school district spokeswoman Venetia Miles said he was active in band and took Japanese before graduating in 1998. He was also in the chess club.
In Elk Grove, he worked as the Pirates Cove Children's Theme Park in 1995. According to the park's director. He had an acceptable employee record.
Kazmierczak had been a student at NIU in the spring of 2007, where he had majored in sociology and served as an officer in at least two student groups. He had been studying at the University of Illinois-Champaign most recently, according to NIU school officials.
Law enforcement authorities told ABC News that Kazmierczak had likely planned the assault on the school for at least five days. All four guns involved in the NIU shooting were purchased legally from the same Champaign, Ill., gun dealer, ABC News has learned.
The Remington shotgun and the Glock 9 mm were purchased Feb. 9, 2008. The Hi Point 380 was purchased Dec. 30, 2007 and the SIG Sauer 9 mm was purchased Aug. 6, 2007, from the same gun dealer.
Authorities were still checking where he obtained two other pistols, a 9 mm Sig Sauer and a Hi Point 380.
He brought the shotgun in a guitar case, police said, and hid the others underneath his jacket.
In a disturbing twist, authorities report Kazmierczak purchased ammunition from the same Web site as the Virginia Tech gunman.
At approximately 3:15 p.m. Thursday, Kazmierczak — dressed in black and armed with three handguns and a shotgun — entered an introductory geology class and opened fire.
While students ran for cover and hid under their desks, Kazmierczak wounded 16 people, killed five others and then himself.
"The assailant began firing into the assembled class from the stage — from the front," NIU president John Peters told ABC News.
"It didn't seem like he was aiming. He just raised a gun and shot immediately," said Paul Sundstrom, a student who was sitting in the class with his brother Kevin when the gunman opened fire.
Police are investigating the shooting, searching for a motive. They say Kazmierczak left no note. They did find a laptop computer, but the hard drive had been wiped.
What set Kazmierczak off and why he chose his former school remains a mystery.
The Associated Press contributed reporting to this story, with additional reporting by ACB News' Luis Martinez, Emily Friedman and Marcus Baram.