The letter is now being tested for ricin. It arrived on Thursday but did not reach the White House (it was picked up at an off-site facility).
The text of that mailing was identical to the letters sent to the mayor and his gun group, which threatened: “what’s in this letter is nothing compared to what I’ve got planned for you,” police and law enforcement sources said.
One letter was discovered at City Hall’s mail sorting facility at 100 Gold St. on Friday, a law enforcement source told NBC 4 New York. It appeared to contain a pink, oily substance when a mail worker came across it and was immediately flagged as suspicious.
An initial field test didn’t bring up any sign of ricin, a source said. But more preliminary testing Wednesday showed the letter tested positive for ricin.
An identical letter containing ricin was sent to the Mayors Against Illegal Guns headquarters in Washington, D.C. and was opened on Monday, police said.
All three letters were postmarked May 20 in Shreveport, La. without a return address.
The NYPD tried to pull fingerprints off the letter discovered at the city’s mail sorting site, but nothing usable was found.
Now authorities also plan to check for any possible DNA on all of the letters.