1. Since gangs, hate groups, and violence in and around public schools have become more prevalent during the last decade, rulings [concerning dress codes] that favor schools are becoming more common when the courts "balance the First Amendment rights of students to express themselves against that legitimate right of school authorities to maintain a safe and disruption-free environment" (LaMorte 1999, 147). This balance is clearly illustrated in Jeglin v. San Jacinto Unified School District (193). In this instance, a school's dress code prohibiting the wearing of clothing with writing, pictures, or insignia of professional or college athletic teams was challenged on the grounds that it violated students' freedom of expression. The court acknowledged that the code violated the rights of elementary and middle school children, but not those of high school students. Gangs, known to be present at the high school, had intimidated students and faculty in connection with the sports-oriented clothing. The court ruled that the curtailment of students' rights did not "demand a certainty that disruption will occur, but only the existence of facts which might reasonably lead school officials to forecast substantial disruption.
2. After the Colorado high school shootings in 1999, which left 14 students and a teacher dead—including the two gunmen who were members of a clique called the "Trench Coat Mafia"—many school districts made their rules for student dress more restrictive. Ten days after the shootings, a federal judge who upheld a school's decision to suspend a student for wearing a T-shirt that said "Vegan" (a vegetarian who doesn't eat animal products), said "gang attire has become particularly troubling since two students wore trench coats in the Colorado shooting." And, in Jonesboro, Arkansas, where four students and a teacher were shot and killed the previous year, a group of boys and girls identifying themselves as the "Blazer Mafia" were suspended for ten days (Portner, May 12, 1999).
3. To reduce disruption and violence in schools, some school districts and policy makers have considered requiring students to wear uniforms. During his last term in office, President Clinton frequently expressed his support for school uniforms; for example, during a conversation with high school students in Alexandria, Virginia, two days after the Colorado shootings, he had this to say about the effects of the nation's first mandatory school uniform policy in Long Beach, California: "it [the uniform policy] distinguished [students] from the gangs, which created a safety problem...it made all the kids safe. And it lowered dropouts, it increased attendance, it reduced discipline problems" (1999). The U. S. Department of Education, which has developed guidelines for schools that wish to implement a uniform policy, reported in 1998 that 4 percent of public elementary schools and 4 percent of middle schools required students to wear uniforms.

Parkay, F.W. & Stanford, B.H. (2001). Becoming a Teacher, 5/e, Boston: Allyn & Bacon, p. 225.