Is there documented evidence tying HC smoke grenade use to specific named federal operations in 2020 beyond Portland?

1. What the strongest documentation shows — Portland and Operation Diligent Valor

Multiple investigations collected spent canisters, analyzed residues, and matched branding and “HC” labels to Defense Technology’s Maximum HC product during the Portland federal deployment; reporters and the Chemical Weapons Research Consortium published lab results finding HC-associated residues including zinc on canisters and clothing, and The Intercept and others linked those munitions to the period when DHS agents were operating under a mission often reported as Operation Diligent Valor ^{[1] [3] [2] [4]}.

2. Claims and denials around nationwide federal deployments — named operations versus ammunition type

While broader 2020 federal deployments are documented in reporting — for example, news summaries that list multiple federal presences and name operations like Operation Legend for separate city deployments — the sources here that chronicle HC smoke focus on Portland and do not present the same kind of chain-of-custody photographic, physical-sample, and residue-analysis evidence for other cities; Wikipedia and reporting note federal forces and the Intercept’s HC reporting particularly in Portland, and Operation Legend and other federal actions were contemporaneous elsewhere, but those sources do not tie HC canisters by lab analysis to those other named operations ^{[5] [1] [6]}.

3. Where reporting hints at broader use — leads that exist but fall short of proof

Researchers and activists suggested HC may have been purchased or used by other agencies or locales (the Chemical Weapons Research Consortium’s press materials report bids and possible uses in Denver and purchases by local police agencies), and some local stories flag purchases or “possible” use outside Portland, but those claims in the provided reporting are conditional and not backed here by the independent, laboratory-confirmed chain-of-evidence present for Portland ^{[2] [3]}. Industry product sheets confirm the existence and labeling of Maximum HC grenades (Defense Technology product files), and several outlets describe the characteristic greenish-white zinc-chloride smoke and its residues when HC is burned — facts that support investigators’ methods but do not, in these sources, substitute for city-by-city samples linking HC munitions to named federal operations beyond Portland ^{[7] [8] [9]}.

4. Official denials, manufacturer behavior, and reporting agendas that complicate attribution

Federal spokespeople and some agency communications have denied possession or use of HC by certain units (the FPS communications director statement denying HC-containing items is reported), and manufacturers or parent companies have been accused of downplaying hazards on safety sheets — these denials and commercial incentives to minimize apparent hazard complicate the public record and create space for contested narratives, but denials do not constitute evidence that HC was not used elsewhere, nor do manufacturer disclosures replace independent residue-based documentation ^{[6] [10]}. Journalistic outlets and activist researchers have different institutional agendas — investigative pieces stressed public-health risks and civil liberties implications (The Intercept, Chemical Weapons Research Consortium), while other coverage emphasized government rationale for deployments — so source intent should be weighed when assessing claims about use beyond Portland ^{[1] [2] [5]}.

5. Bottom line

The assembled reporting and laboratory-based investigations reliably document HC smoke grenade use during the Portland federal deployment (linked in popular reporting to Operation Diligent Valor), but within the set of sources provided there is no equivalently documented, independently verified chain of physical evidence that ties HC smoke grenade use to other specifically named 2020 federal operations outside Portland; the record beyond Portland is suggestive in some activist materials and purchase records but not conclusively documented here ^{[1] [2] [3] [5]}.