Crypto and blockchain forensics expert witness in Spain
I analyse the blockchain with an expert witness method: fund tracing on Bitcoin, Ethereum and its L2s, wallet and exchange hacks, DeFi exploits, smart contracts and crypto assets in inheritance, divorce and insolvency cases.
Member of AEPEJU (no. 1556). Barcelona and across Spain.
What a crypto forensics expert witness does
They turn what the blockchain records into a report that a judge can understand and check. Transactions are public, but addresses are pseudonymous and funds hop between chains, protocols and services.
My job is to read that trail methodically, separate facts recorded on-chain from inferences, and state at every step how certain each statement is. I sign the report under an oath of objectivity, as required by article 335 of the Spanish Civil Procedure Act (LEC), and I defend it in court.
Services: one page for each type of case
Each service has its own page with the detail, frequently asked questions and what I need to get started. Most of those pages are in Spanish; the report itself can be delivered in English.
- Crypto tracing: from the source transaction to the destination exchange, on Bitcoin, Ethereum, its L2s and tokens such as USDT.
- Crypto scams: fake brokers, romance investment scams and phishing. Report for the police complaint.
- Wallet or exchange hacks: drainers, malicious signatures, leaked seed phrases and SIM swapping, analysing the device and the chain together.
- DeFi exploits: reconstruction of the attack on a protocol or bridge, and tracking of the funds.
- Smart contract expert analysis and security review in Solidity and Cairo: what the deployed code really does.
- Crypto in inheritance cases: locating and valuing assets at the date of death.
- Crypto in divorce cases: signs of undeclared crypto assets and valuation at a given date.
- Insolvency and seizures: locating crypto assets and outflows of assets.
- Wallets and exchanges: address attribution and reconciliation of exchange statements.
Why an expert with real on-chain experience
Because blockchain analysis is learnt by investigating real cases. I am a blockchain data engineer at MigaLabs, an Ethereum research lab in Barcelona, and I have a merged contribution to the Ethereum Beacon API specification.
I co-authored the forensic analysis of the KelpDAO exploit: a forged cross-chain message released 116,500 rsETH, roughly 294 million dollars; the attacker extracted 75,700 ETH through Aave v3 and Compound v3, and the funds ended up converted into 1,329 BTC via THORChain. It is the same method I apply to every case.
I am also a court expert in digital forensics, member of AEPEJU no. 1556. That lets me analyse the victim's phone or computer and what happened on-chain in the same report, which a single expert rarely does.
What the report looks like
It is written for the court, not for specialists. It includes a fund-flow graph, a table of transactions with hash, block, date and amount, and links to public block explorers so anyone can check every figure.
- Facts recorded on-chain, separated from inferences.
- Stated degree of certainty at every hop.
- Methodology described so another expert can reproduce it.
- Conclusions in plain language, without stepping into what the judge must decide.
Limits you should know
Tracing is not recovering. The blockchain does not reveal identities: the identity comes from the exchange when the court requests it, and any recovery depends on that court action.
- Mixers and privacy protocols reduce the certainty of tracing, and the report says so.
- Without the seed phrase or private key nobody can move funds from a self-custody wallet, an expert included.
- I do not charge a percentage of anything recovered and I do not promise results: I sign a report and answer for it in court.
Frequently asked questions
Common questions about this kind of report.
Which chains do you work with?
Bitcoin, Ethereum and its L2s (Arbitrum, Optimism and Base), and tokens such as USDT on those networks. If funds move to another chain, I state how far the tracing goes and with what certainty.
Can the report be used in court in Spain?
Yes. It is a signed expert report with a reproducible methodology, which can be filed with a police complaint or a claim, and I ratify it in court if needed.
Can you access a wallet without the seed phrase?
No. Without the seed phrase or private key nobody can move the funds, but I can establish the balance and history of the known addresses.
Do you work for victims, companies or law firms?
All three, as a party-appointed expert, and I accept court appointments. Often the case comes through the lawyer handling it.
Do you work on international cases?
Yes. I work in Spanish, Catalan, English and French, and I can deliver the report in English for international firms, protocols and insurers.
How much does a crypto forensics report cost?
It depends on the number of transactions and hops. The first 30-minute consultation is free and a fixed written quote arrives within 24 working hours.
Tell me about your case
Free 30-minute consultation and a free quote within 24 working hours.