When a school suspects a student is in possession of illegal drugs or prescription medications without a proper prescription—or is under the influence of drugs or alcohol—the school may want to search the student’s pockets, backpack, or locker, for example. And if the school suspects the student is under the influence of drugs or alcohol, the school may want the student to submit to testing. 
 
A search of a student’s pockets, backpack, or locker, for example—or a search of the student’s body/person through a urine, blood, or breath test, for example—are generally considered searches that implicate the Fourth Amendment of the U.S. Constitution when the searches are performed by a governmental entity such as a public school. The Fourth Amendment protects citizens from unreasonable searches and seizures. But in the context of schools, the courts have tried to balance the individual’s rights with the need to maintain a safe learning environment—which has led to some unique legal interpretations.
 
U.S. Supreme Court Rulings

Here is a summary of some of the important U.S. Supreme Court decisions on this topic:
 
·      New Jersey v. T.L.O. (1985). The U.S. Supreme Court ruled that although students have a legitimate expectation of privacy, schools have a unique interest in maintaining a safe environment for students and teachers. Thus, school searches—including locker searches—are permissible if school administrators have “reasonable suspicion” of illegal activity. This is a lower standard than the probable cause usually required for a government official to search a person or place in which the person has a reasonable expectation of privacy.
 
·      Vernonia School District v. Acton (1995). The U.S. Supreme Court upheld the constitutionality of drug testing student athletes. The Court held that the student athletes had a lower expectation of privacy due to communal undress in locker rooms and a history of drug use in this school’s athletic programs.
 
·      Board of Education v. Earls (2002). The U.S. Supreme Court extended the ruling from the Veronia case and allowed random drug testing for all middle school and high school students participating in competitive extracurricular activities—not just athletics.
 
Although the U.S. Supreme Court has set some broad standards for drug testing in schools, many states and school districts have their own laws and policies regarding student drug testing. Some states and districts may have greater protections for student privacy, while others may give schools greater latitude to conduct testing. 
 
It often cannot be said with certainty whether such policies are constitutionally permissible until they are tested in the court system. Lower court rulings—from courts below the U.S. Supreme Court—that only apply in certain states or districts (state courts and federal courts) may provide additional guidance on school drug testing policies.
 
General Rules Regarding Drug Testing
Generally, only students in extracurricular activities such as sports, clubs, or other competitive activities can be subjected to random drug tests. Unless a student is involved in such an activity a school generally must have a specific reason to believe a student is using drugs (a reasonable suspicion)—although the nature of the specific reason or reasonable suspicion is a debated issue with varying interpretations from state to state and among school districts within states. 

Schools generally cannot conduct blanket drug tests of all students or random drug tests on the entire student population. 

Consent

Schools may often seek consent from students and their parents or guardians—through a signed consent form—to submit to random drug testing, for example, as a condition of participating in extracurricular activities. Consent from a student and the student’s parent or guardian will generally prevent the student from challenging the constitutionality of the drug testing. 

In Pennsylvania, schools have the authority to search students or request drug testing if there is reasonable suspicion of drug possession or influence, in line with the Fourth Amendment. The U.S. Supreme Court has established that such searches are permissible with 'reasonable suspicion' rather than the 'probable cause' required for law enforcement. Additionally, the Court has allowed drug testing for student athletes and those participating in extracurricular activities. While state and district policies in Pennsylvania may vary, random drug testing typically applies only to students engaged in extracurricular activities, and schools must have a specific reason to test other students. To avoid constitutional issues, schools often obtain consent from students and parents for drug testing. This consent process helps to ensure that the rights of students are respected while allowing schools to maintain a drug-free environment.