AML Lookback Closure Cycle

Note (dated 2026-08-04): a chain composes independent computations performed in an analytical order. No step's output is carried into the next step by the execution model; each step computes from its own declared inputs. This is true of every chain on this site, including chains whose per-step copy below reads as a data handoff.

Reading mode (RUNBOOK): Run these steps in order. Each step works the prior step’s output (the reconciled population feeds the sample frame, the sample frame feeds the disposition rollup), so the order above is the order a lookback team actually works the file in.

Three-step BSA/AML lookback closure cycle over the re-screened population, the resulting disposition sampling frame, and the caller's own per-sampled-item disposition records. Step 1 reconciles re-screening completeness against the declared population, excluding any period with no preserved list snapshot as unverifiable rather than screening it against today's list. Step 2 builds a deterministic disposition sampling frame and reviewer workload allocation over the verifiable population. Step 3 rolls up disposition-coverage, disposition-rationale-presence, and a population-to-sample tie-out into a closed gate value. A hold or escalate outcome routes the cycle to the BSA Officer as reviewer; a completed lookback, including an auto_pass rollup, still requires a separate approval record naming the BSA Officer or designated compliance role as approver. Customer id, alert id, and transaction reference are salted throughout; no plaintext identifier ever enters the chain. This bundle is the institution's own evidence of its lookback closure basis, not a supervisory determination.

OpenChainGraph · 3 Steps compliance control Hash-Anchored §4 chain_depth:3 Client-Side · Zero PII

Chain Stages · 3 Steps

1 ROOT node

Lookback Completeness Reconciler art-470-lookback-completeness-reconciler

verifiable_source_count, verifiable_extract_count, and unverifiable_periods (excluded from re-screen scope) feed the disposition sampling frame's population definition; population size also feeds the rollup's population-to-sample tie-out

MCP Call · reconcile_lookback_completeness

{
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "name": "reconcile_lookback_completeness",
    "arguments": {}
  },
  "id": 1
}

↓

2 D2 node

Disposition Sampling Frame art-471-disposition-sampling-frame

reviewer_workload allocation and the sample frame's declared population size feed the disposition rollup kernel, alongside the caller's per-sampled-item disposition records

MCP Call · build_disposition_sampling_frame

{
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "name": "build_disposition_sampling_frame",
    "arguments": {}
  },
  "id": 1
}

↓

3 TERMINAL node hold / escalate → BSA Officer

AML Lookback Disposition Rollup art-534-aml-lookback-disposition-rollup

Disposition-coverage, disposition-rationale-presence, and population-to-sample tie-out roll up into a closed §27.4 gate_policy value that closes the lookback's evidence bundle. Final stage.

§27 Human Accountability gate: a hold or escalate rollup routes the cycle to the BSA Officer as reviewer before it is treated as settled. A completed lookback, including an auto_pass rollup, still requires a separate approval record naming the BSA Officer or designated compliance role as approver (§27.1); automation never substitutes for that named sign-off.

MCP Call · roll_up_aml_lookback_disposition

{
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "name": "roll_up_aml_lookback_disposition",
    "arguments": {}
  },
  "id": 1
}