"The Drug Enforcement Administration (DEA) Philadelphia Field Division (PFD) Intelligence Program maintains situational awareness of drug availability, abuse, trafficking patterns, adulterants, concealment methods, etc., through analysis of law enforcement and public health information and data, as well as law enforcement source information. [...] Data analyzed in this report was generated by 11 federal/state/local laboratories. Heroin exhibits analyzed and reported to NFLIS [National Forensic Laboratory Information System] in Pennsylvania totaled 145,159 from 2006 through 2016, with annual increases between 2011 and 2015 followed by a slight decline in 2016. The slight decline in heroin presence coincided with a sharp increase in fentanyl identifications. The inclusion of fentanyl in the illicit drug market generates questions regarding fentanyl marketing and sales techniques; user knowledge and/or pursuit of fentanyl versus heroin; and the potential for fentanyl to replace heroin in the user market."
DEA-PHL-BUL-065-18; Drug Enforcement Administration Philadelphia Division Bulletin 065-18
Drug Enforcement Administration: https://www.dea.gov/