BOSTON (WBZ-AM) -- A forensic science expert explained several of the techniques law enforcement could be using to trace an envelope full of white powder that was sent to Donald Trump Jr. Monday.
Trump Jr.'s wife, Vanessa Trump, opened the suspicious letter and was taken to a Manhattan hospital as a precaution and later released, but investigators do not believe the substance in the envelope was hazardous.
ABC News reported that the letter was postmarked in Boston.
Dr. Lawrence Kobulinsky, a professor of forensic science at John Jay College of Criminal Justice in New York City, told WBZ NewsRadio 1030's Carl Stevens that the letter brought to mind more serious attacks of the past.
"Clearly the letter is frightening, because when you don't know what is inside of it, it brings back memories of the anthrax attacks that took place not so long ago," he said.
He detailed the clues that may be derived from the letter.
"The envelope itself has writing on it," he said. "Presumably there's a stamp, and the envelope may or may not have been moistened with saliva to seal it. If there's saliva on either the stamp or the envelope, there's DNA, and that is a major factor in breaking the case. If there's writing on the envelope, and presumably there is, then there's handwriting analysis."
There's also the possibility of DNA or fingerprints on the letter itself--but Dr. Kobulinsky said the main thing is to find out exactly what kind of material was sent, and to preserve that material for future analysis.
"The trick then is, can you trace it back to its origin?" he said. "That is really the strength of law enforcement here. Is there some sort of postal mark over the stamp? Where was it mailed? Things of that sort to try to track back where it originated from."
Dr. Kobulinsky said it's important to analyze the letter, because then it can be compared with any potential future envelopes sent to other people.
WBZ NewsRadio 1030's Carl Stevens reports