Missing Files Motivated the Leak of Michael Cohen's Financial Records
A law-enforcement official released the documents after finding that additional suspicious transactions did not appear in a government database.

In the days since, there has been much speculation about who leaked the confidential documents, and the Treasury Department's inspector general has launched a probe to find the source. That source, a law-enforcement official, is speaking publicly for the first time, to The New Yorker, to explain the motivation: the official had grown alarmed after being unable to find two important reports on Cohen's financial activity in a government database. The official, worried that the information was being withheld from law enforcement, released the remaining documents.

The report also refers to two previous suspicious-activity reports, or sars, that the bank had filed, which documented even larger flows of questionable money into Cohen's account. Those two reports detail more than three million dollars in additional transactions--triple the amount in the report released last week. Which individuals or corporations were involved remains a mystery. But, according to the official who leaked the report, these sars were absent from the database maintained by the Treasury Department's Financial Crimes Enforcement Network, or fincen. The official, who has spent a career in law enforcement, told me, "I have never seen something pulled off the system. . . . That system is a safeguard for the bank. It's a stockpile of information. When something's not there that should be, I immediately became concerned." The official added, "That's why I came forward."