Green addressed reporters and members of the public Monday afternoon, displaying the letter and expressing frustration about the incident.
“Yes, I am upset,” Green said. “I’m upset because I am charged with the responsibility of protecting the staff that’s here and also the public that comes into this area.”
Authorities found the envelope Oct. 16 at the federal building at 1919 Smith St. The building houses the offices of federal officials, including U.S. Sen. Ted Cruz and U.S. Rep. Christian Menefee, as well as a U.S. passport agency and an immigration court.
“If the person is doing this as a joke, it’s not funny,” Green said. “There are too many things happening, and too many people are concerned, for us to consider this funny.”
Green said the envelope was found Friday but that Monday’s news conference was the first time he had seen it in person.
The letter displayed at the news conference appeared to have been mailed from San Antonio and dated Oct. 13. It was addressed to Green at 3003 South Loop and included a suite number.
An employee reported finding the substance after opening the envelope, the Houston Police Department said, according to previous Houston Chronicle reporting.
Green said officials had not determined whether the substance was harmful.
Members of Congress do not open their own mail, Green said. Staff members use specialized equipment to screen and open it.
As authorities continued to investigate, The Washington Sun reported that letters containing suspicious powder had been mailed to lawmakers across the country. Preliminary tests found that substances in some of the letters were not hazardous, according to the outlet.
As of Oct. 19, 40 members of Congress had reported receiving suspicious mail, the outlet reported.
Cruz, who was among the lawmakers who received a letter, described the incident on X as “deeply concerning.”
Green could not confirm whether the letter delivered to Cruz was connected to the one sent to his office, but he said the letters had similarities.
“This is intolerable. We won’t tolerate it, and we also won’t be intimidated,” Green said.
The Chronicle contacted the FBI for more information but did not receive an immediate response.