Increasing presence of xylazine in heroin and/or fentanyl deaths, Philadelphia, Pennsylvania, 2010–2019 Posted on October 28, 2022 By Becky Carter Jewell Johnson, Lia Pizzicato, Caroline Johnson, Kendra Viner Inj Prev; 27(4); 2021 Access article Forensic Pathology and Medicolegal Death Investigation, Statistics and Data Analysis, Toxicology