The Putnam County Public Library District will hold a free screening of the documentary “The Poisoner’s Handbook” at 4 p.m. Thursday, Oct. 30, at the library’s Condit branch, 105 N. Center St., Putnam.

The documentary tells the story of how early 20th-century Americans’ medicine cabinets featured radioactive radium, thallium, and morphine in everyday products. The science needed to detect and prevent crimes involving the substances was falling behind industrial innovation. New York City appointed Charles Norris, its first scientifically trained medical examiner, in 1918. Norris partnered with chief toxicologist Alexander Gettler to transform forensic chemistry.

For more information, call 815-339-2038.