On Wednesday, HazMat teams checked out letters at Barbara Bush and Crockett elementary schools. Today, it was Condit Elementary School in Bellaire.
Officials say staff discovered a package Thursday morning similar to yesterday's letters found with white powder inside them. But they did not open today's package. Instead, they called authorities, who kept it away from children while a postal inspector took the envelope.
Police have not said if today's package was connected to those found yesterday. But even if it's some kind of hoax, the person behind it could face federal charges.
"It's not funny. We take it very seriously. And we are not going to let our guard down. We will be as diligent on every call as we were on the first one," said Asst. Chief Robert Mock with the HISD Police Department.
The FBI will test the envelope. They found Wednesday's substance was not harmful.