David Leff

Forensic Narcotics Expert, Greater Philadelphia area

Forensic Narcotics Expert, Greater Philadelphia Area

I have been involved in the investigation and interviews of over ten thousand drug cases over the past 38 years, from Providence RI to Wash DC. I am equally available to both the defense and prosecution, to assist in a forensic analysis of their cases and to testify in court, if appropriate. My main focus for my position, is the distinction of what constitutes drug(s) for personal use, as opposed to the intent to deliver. All collateral issues, such as; quantity, packaging, paraphernalia, drug effects, multiple person distribution schemes, use of "mules", adulterants, value, stashes, USC, wiretap/email intercept interpretation, drug supply resulting in death, tally sheets, weapons, trafficking/transportation, international drug trafficking, etc., are also considered and testified as an expert, when necessary.

With the notification to all Phila Narcotics Units, (NETS, NSF, NFU), I have spent months in the 3rd, 24th, 25th, & 26th police districts, mostly at night-walking, speaking to drug users and drug dealers. I have been offered to buy cocaine, crack, heroin, Suboxone, Fentanyl, pills, works, etc. 100+ times. I have seen active drug dealing and the use/placement of stashes. I have witnessed hundreds of times; the use of marijuana, crack, and heroin-via snorting & IV.

Specialties: I assist legal counsel in their understanding of drug usage, packaging and the methodology of drug trafficking-at all levels. When my opinion is favorable, I testify at trial.