An envelope addressed to the White House and apparently containing cyanide was caught by off-site screeners before it got anywhere near the president, the Secret Service says. A spokesman says the package initially tested negative for the poison after it was received at the White House Mail Screening Facility on Monday but it tested positive during chemical screening yesterday and a lab is working to confirm the results, CNN reports. Officials say that the person who opened the letter at the screening facility was not exposed.
According to a law enforcement alert seen by the Intercept, the screening facility received an "envelope containing an unknown milky substance, in a container wrapped in a plastic bag." The alert says the return address belongs to a man who has been known to the Secret Service since 1995, when he sent a package covered in urine and feces to the White House. The person has sent other packages over the years, according to the alert, most recently "mini alcoholic beverages" in June 2012. (The Secret Service is seeking $8 million to build a fake White House.)