The FBI confirmed in a letter filed in court last week what nearly everyone already knew for months — that they have an open investigation into Hillary Clinton’s unauthorized home-brew e-mail system. The letter came as a necessarily belated response to a State Department inquiry last September into what the FBI was doing with the issue. At the time, the FBI played it close to the vest, but now there’s not much point in maintaining a pretense of secrecy.

Wall Street Journal reporter Byron Tau first broke the story on Twitter:

The timing on this development could not be worse for Hillary Clinton, who insisted on Thursday night that the FBI was simply conducting “a security review”:

Er, yeah … not exactly. Note the last line in the letter, emphasis mine: “[W]e remain unable to provide the requested information without affecting on-going law enforcement efforts.” A “security review” is not a law-enforcement effort; a law enforcement effort would follow a security review. In fact, the security review has been conducted by the Inspectors General at State and the intelligence community, which has found more than 1500 instances of classified information transmitted through and retained by the unauthorized and non-secure system Hillary personally put in place for her electronic communications.

Fox News’ Catherine Herridge and Pamela Browne debunked the “security review” claim from Hillary over the weekend:

Not true says Steve Pomerantz, who spent 28 years at the FBI, and rose from field investigative special agent to the rank of assistant director, the third highest position in the Bureau.

“They (the FBI) do not do security reviews,” Pomerantz said. “What they primarily do and what they are clearly doing in this instance is a criminal investigation.”

Pomerantz emphasized to Fox News, “There is no mechanism for her to be briefed and to have information about the conduct, the substance, the direction or the result of any FBI investigation.”

Separately, an intelligence source familiar with the two prongs of the ongoing FBI probe, stressed to Fox that the criminal and national security elements remain “inseparable.”  The source, not authorized to speak on the record,  characterized Clinton’s statement “as a typical Clinton diversion… and what is she going to say, “I’m 95 percent sure that I am going to get away with it?”

Fox recently learned that one of the FBI’s senior agents responsible for counterintelligence matters, Charles H. Kable IV, is working the Clinton case, another indicator the intelligence source said that the FBI probe is “extremely serious, and the A-team is handling.”

Indeed. The FBI might not be able to name its targets, but they’re making it pretty clear that they have targets to name, eventually.