How many CSAM investigations were opened by federal agencies each year from 2015 to 2024?

1. Why the question is harder than it sounds: reports versus investigations

Most public documents track referrals, reports, prosecutions, or task‑force staffing rather than a simple count of “investigations opened” by federal agencies; for example, the National Center for Missing & Exploited Children’s CyberTipline annual totals and DOJ materials document millions of reports and rising federal production cases, but those are distinct metrics—reports received, referrals to law enforcement, or prosecutions initiated—not a direct tally of federal investigative openings ^{[1] [5] [3]}.

2. What the record does show about reporting volume (useful but not equivalent)

NCMEC’s CyberTipline experienced explosive growth: 4.4 million reports in 2015 and roughly 29–36 million reports in later peak years are cited in the supplied materials—NCMEC totals are explicitly mentioned as 4.4 million and “nearly 30 million” in 2021, and separate sources cite 35.9 million in 2023 and other multi‑million figures for 2024—but those figures reflect platform and public reporting volume, not federal investigative starts ^{[1] [2] [3]}.

3. Federal prosecutorial and investigative snapshots are fragmentary

Justice Department documents note that federal “production” cases have risen—citing that production cases almost tripled from an earlier baseline of 218 initiated cases over an 11‑year span—but the DOJ sources provided do not translate that trend into a complete annual series of investigations opened by federal agencies from 2015 to 2024 ^{[1] [2]}. Similarly, Congressional and ICAC materials document 61 task forces and more than 5,400 participating agencies, showing capacity and coordination but not an annual federal case‑opening count ^{[6] [7] [4]}.

4. Conflicting or ambiguous figures in the supplied reporting

The sources include apparently inconsistent statements about 2023–2024 volumes (for instance, some texts say NCMEC received over 35.9 million reports in 2023 while another place lists “26,823 reports” for 2024), indicating differing denominators or subsets (e.g., reports referred to law enforcement, vendor reports, or a narrow category of federal referrals) rather than a single national investigative count; the materials do not reconcile those numbers or label them as “investigations opened” by federal agencies ^{[5] [3]}.

5. What would be required to answer the question accurately

An authoritative year‑by‑year count of federal CSAM investigations opened would require direct, standardized disclosures from the federal investigative agencies (FBI, HSI, U.S. Attorney offices, DOJ Criminal Division, etc.) or a compiled dataset showing referrals from NCMEC to federal agencies and whether those referrals resulted in an opened federal investigation; none of the supplied documents supply that comprehensive annual series for 2015–2024 ^{[8] [9] [4]}.

6. Bottom line and recommended next steps for definitive numbers

Based on the provided sources, it is not possible to produce a verified table of “CSAM investigations opened by federal agencies” for each year 2015–2024; available documents supply related indicators—CyberTipline report volumes, federal production case trends, and ICAC capacity—but not the requested annual investigation counts ^{[1] [2] [6]}. To obtain the precise series requested, one should request (a) FOIA or public‑records disclosures or annual statistics from DOJ and FBI, and (b) NCMEC’s referral logs that specify how many CyberTipline reports were forwarded to federal agencies each year and how many of those referrals led to investigations, because those are the data points that would be needed to construct the series ^{[5] [8]}.