Absolutely essential at the outset of any investigation is the securing of the integrity of the crime scene. All too often, investigators arrive at the scene to find the original condition disturbed by family members or bystanders whose often-zealous attempts to be helpful destroy valuable evidential items. Teach your students how to quickly and efficiently establish and maintain tight control over crime scene perimeters with this brilliant yellow warning tape from Sirchie®. Simply tie 1 end of the tape around a fixed item, walk around the scene's perimeter and tie it off where desired. Eye-catching black lettering, "CRIME SCENE DO NOT CROSS," is printed on brilliant yellow polyethylene. The tape is 3" wide by 1,000 ft long. The warning repeats every 31". A dispenser box is furnished with each roll.