Just days after the Boston Marathon bombing, more frightful events are making headlines. Officials report that letters addressed to President Obama and U.S. Senator Roger Wicker tested positive for poison. The substance that raised concern may be a poison called ricin, which CNN describes as “a highly toxic substance derived from castor beans.” However, it is possible another organic substance triggered a false positive test result.

Unlike the bombings in Massachusetts, police sources told Time Magazine that they have a suspect in the Roger Wicker letter case, but declined to comment on the individual or the on-going investigations. According to Time, there is no evidence of a connection between the letter and the Boston Marathon attack. Events were already canceled at the U.S. Capitol after the bombings, and the discovery of these letters raised additional concerns among congressional officials. So far, no information has been released about a motive in these cases, or why either leader was targeted.

Many people remarked that the Boston Marathon bombing brought back the tragic memories of September 11th, and these possibly-poisoned letters are certainly reminders of the 2001 anthrax attacks, which killed five people. It was the very protocols put in place after those anthrax attacks that identified the letter sent to Rep. Wicker yesterday, and we are thankful that the security measures worked. The Maryland mail facility, where one of the ricin letters was detected, will be closed for a few days while the Capital Police and the FBI continue the investigation. In the coming days, more information will likely be available about the Boston bombing and the suspicious letter. Stay tuned.