In an interview with WNYC on Wednesday evening, NYPD spokesman Paul Browne said the letter sent to Mayor Bloomberg that preliminarily tested positive for the poison ricin is the first of its kind in the city since the anthrax attacks in weeks after 9/11.
Browne said a letter opened at a city government building on Gold Street on Friday, and one opened by the head of Mayors Against Illegal Guns in Washington on Sunday, threatened the mayor and made references to the debate on gun laws. He said it's not unusual for the NYPD to investigate threat letters with powders, but that this one was different.
"Since the aftermath of 9/11 with the anthrax letters, this is to the best of my recollection...the first ricin or toxin that indicates the presence of this toxin in a letter," Browne said.
Browne said the address on the letter sent to New York was suspicious, and a worker who took precautions while opening it was not harmed by the ricin.
"They took the precautions that have been in place since 9/11," he said.
Browne said the worker inserted gloved hands inside a protective box to open the letter without coming into contact with it. Three NYPD officers who handled the letter were treated for mild symptoms of ricin exposure that have since abated.
A lab in Maryland is conducting further tests on the letters, and the FBI and NYPD are investigating who sent them.