New Jersey Statutes Title 2C. The New Jersey Code of Criminal Justice 2C § 20-14

a. A law enforcement officer, a special officer, or an employee of a library facility who has probable cause for believing that a person has willfully concealed library material and that he can recover the material by taking the person into custody, may, for the purpose of attempting to recover the material, take the person into custody and detain him in a reasonable manner for a reasonable time. Taking the person into custody shall not render the law enforcement officer, the special officer, or the employee of a library facility civilly or criminally liable.

b. Any law enforcement officer who has probable cause for believing that a person has committed the offense of theft of library material may arrest the person without warrant.

c. An employee of a library facility who causes the arrest of a person for theft of library material, as provided for in this act, shall not be civilly or criminally liable where the employee has probable cause for believing that the person arrested committed the offense of theft of library material.