SARs & CTRs
Two FinCEN filings: a Currency Transaction Report for cash transactions over $10,000 in one business day (aggregated), and a Suspicious Activity Report for transactions of $5,000 or more that look like laundering or have no business purpose.
Tipping off the subject of a SAR is a federal offense — confidentiality is absolute. CTRs aggregate multiple same-day cash deposits, which is exactly what structuring tries to evade.