Police arrested Nahum Reynaldo Castro, 40, this week on charges he stole Bitcoin from his former employer — a crime that went undetected for nearly five years until the victim opened a safe and found the hardware wallet empty. The stolen cryptocurrency was worth just over $217,000 at the time of the theft in 2020 and had ballooned to more than $1.9 million by July 2025, when the loss was discovered. Castro faces counts of grand theft, money laundering, unlawful use of a communications device, and offenses against computer users.
The theft and the safe
The victim started buying Bitcoin in December 2017 as a long-term hold, storing the private keys on a hardware wallet locked inside a safe. Only two people knew the wallet's seed phrase: the owner and Castro, who handled IT and security for the company. Castro worked as a trusted employee starting in 2013, tasked with setting up and maintaining the wallet. At some point in 2020, the funds were drained. The victim didn't notice until July last year, when he opened the safe for a routine check and found the wallet empty.
Bank records broke the case
Prosecutors used bank records showing deposits into Castro's accounts that matched the timing and amounts of withdrawals from the Bitcoin wallet. That financial trail, along with the fact that no one else had access to the seed phrase, made Castro the prime suspect. He continued working for the victim until 2024, four years after the theft, apparently undetected.
An insider with access
Castro wasn't just any employee — he was the IT specialist who built the wallet's security setup. That gave him the knowledge and the physical opportunity to grab the seed phrase. The charges reflect a breach of trust that lasted years. He has not entered a formal plea and is set to appear in bond court.
What comes next
Castro remains in jail awaiting a bond hearing. The court will determine release conditions, and a formal arraignment will follow. The victim is out $1.9 million in crypto that likely won't be recovered — but the case shows how long a Bitcoin crime can stay hidden when the thief is the one guarding the keys.
