Dallas Independent School District said it budgeted as much as $12 million to install window film at dozens of campuses. Nashville’s public schools put up $3.5 million. The school district in New Rochelle, N.Y., spent $5.5 million on film and security glass, according to contracting-data provider GovSpend. A spokeswoman for Avery Dennison, an Ohio based window-film manufacturer for the past three decades, said the company makes no claims of “being bullet-resistant, bulletproof, or meeting bulletproofing standards” and doesn’t market its film as a means to prevent intruders.