A list of thirty selectors and a graph of thirty selectors contain identical information, and only one of them lets you see that two clusters share a node. That is the entire justification: humans do not detect shared elements across rows, and detect them instantly in a layout. The beginner mistake is treating the graph as an output — a picture drawn at the end for the report. It is the case's working memory, built from the first pivot, and the report is generated from it.

Everything useful downstream — deduplication, centrality, querying, the report table — depends on decisions made in the first ten minutes. Two rules:

One node per real-world thing. An alias is an attribute, not a node. If "J. Okonkwo", "jokonkwo", and "Joseph Okonkwo" are three nodes, every metric you compute is wrong: degree is split three ways, so the most important person in the case looks peripheral, and the shared connection between two clusters never appears because it is distributed across duplicates. Merge on evidence and record the merge (which selectors, what confidence) — an unrecorded merge is an unauditable assertion that two things are one thing.

The exception that trips people: a person and their account are different things. Model , because the operator can change and the account can be shared. Collapsing them makes both facts unrepresentable.

A closed set of edge types. Free-text edge labels produce , , , and in one graph, and no query ever finds them all. Fix the vocabulary, keep it small, keep direction consistent, and write it at the top of the case file. Starter schema with entity types, edge types, required attributes, and the alias/merge convention: reference/schema-starter.md.

This is the practice that separates a useful graph from a pretty one, and it is the one most often skipped.

Node provenance is almost never the issue. The claim is in the relationship: "this person controls this company", "this domain is operated by this actor". Every edge therefore carries at minimum: source (URL, tool, or exhibit ID), retrieval timestamp, source grade (see ), and confidence. Without it, an edge asserted by a registry filing and an edge inferred from two accounts posting similar text render identically — and once drawn, a weak link is indistinguishable from a strong one and gets reasoned over as fact.

Render confidence visually: solid for confirmed, dashed for probable, dotted for unconfirmed. Then look at your graph and notice how much of the structure you were relying on is dotted. Keep a view and check whether your conclusion survives it — if it collapses, your finding is an artefact of your weakest edges.

Add temporal validity — / — to any edge that can end: employment, domain registration, address, directorship, IP resolution. A graph without time silently asserts that everything coexisted, which manufactures relationships between people who never overlapped. Two directors of one company five years apart are not connected; an untimed graph says they are.

Treat centrality as a pointer to where to look, never as a conclusion. It measures your collection as much as reality: whatever you enumerated most thoroughly becomes the centre of the graph.

Honest default: for most investigations, two CSVs — nodes and edges — plus a simple renderer beat every heavyweight tool. They are diffable, version controllable, reviewable by someone who has never seen the tool, and they import into all of the above. Adopt Maltego or Neo4j when you have a reason (transform automation, or graphs too large to hold in your head), not by default.

Maltego's model is worth understanding even if you don't use it: entities carry transforms, which are server-side lookups turning one entity into related ones (domain to subdomains to IPs to certificates). Transforms are collection, so each one is a network action attributable to you, and each result arrives with whatever accuracy the underlying data source has. Maltego's own graph is the authority on the transform's output, not on the world.

Cypher is worth learning for one reason: path queries. Asking "is there any chain of at most four relationships between this person and that company, and what is it" is a query in Neo4j and a manual slog anywhere else.

MATCH p = shortestPath((a:Person {id:'p-kestrel'})-[*..4]-(c:Company {id:'c-nordvale'}))
RETURN p

Feature comparison, import formats, the Gephi CSV column names, and when each tool is the wrong choice: reference/tool-comparison.md.

Over-connection. The classic failure. Enough edges and everything connects to everything; the graph becomes a hairball and stops carrying information. It happens through low-value edges: same country, same registrar, same hosting provider, same webmail domain, same popular CDN IP. Two sites on Cloudflare are not related. Two people with Gmail addresses are not related. Rule: an edge earns its place only if it discriminates — if a large fraction of unrelated entities would share it, it is context, not a relationship. Model those as node attributes, or leave them out.

Shared-service edges misread as relationships. Shared hosting, a registrar privacy service, a company formation agent's registered address, a payment processor, a mail-forwarding suite: all produce genuine shared nodes and no relationship between the parties. Always ask how many other entities touch that node — a registered address with four hundred companies is an agent's address.

Entity resolution errors, both directions. Splitting one person into three (hides the finding) and merging two people into one (invents it). Merging is the more dangerous, because the graph then looks like strong corroboration: two clusters joined by a merge you performed. Record every merge with its evidence and be able to unmerge.

Confidence laundering by layout. A dotted inferred edge gets drawn, then screenshotted, then described in prose, and three steps later it is a line in a diagram in a report that nobody can trace. Generate report figures from the data file, never from a hand-edited picture.

The graph as argument. A well-laid-out graph is persuasive out of all proportion to its evidence. Layout algorithms are aesthetic; adjacency in a force-directed picture is not a finding. Cite the edge, not the image.

Metrics on an incomplete graph. Centrality on a graph you built by enumerating one actor exhaustively will crown that actor. Note collection coverage next to any metric you report.

Grade edges, not the graph.

A path is only as strong as its weakest edge. State the minimum edge confidence along any chain you report, not the average.

Case: three fraud domains, apparently unrelated. Nodes and edges kept in two CSVs from the first pivot.

WHOIS is privacy-protected on all three, so registrant edges are unavailable — the obvious approach is a dead end. Archived copies via turn out to include pre-privacy registration snapshots for two of them, giving two edges, sourced and dated, graded confirmed.

Adding IP resolutions creates an apparent hub joining all three plus forty unrelated sites: a shared CDN address. Degree makes it the most central node in the graph, which is meaningless. It is downgraded to a node attribute and removed as an edge — the hairball disappears with it.

The real bridge is a self-hosted analytics identifier present in the archived HTML of two domains and on a fourth site not previously in scope, a personal portfolio carrying a real name. Betweenness on the confirmed-only view puts that identifier, not the visible registrant, between the two clusters. Temporal edges show the portfolio's use of the identifier ended before the third domain existed, so that domain stays unconnected — and saying so keeps the report honest.

A case graph is a purpose-built profile of identified people, and it is more sensitive than any single item in it — aggregation is the point of the technique, and aggregation is what data-protection regimes scrutinise. Third-party nodes accumulate fast (relatives, colleagues, co-residents); prune anyone not relevant to the objective before the graph goes anywhere, and redact them from published figures. Store the graph file with the same encryption and retention rules as the rest of the case per ../../ETHICS.md. Hosted graph platforms mean uploading the case to a third party — check that is permitted before you paste a subject's selectors into a cloud transform.