Last week, Denver officials arrested a young Afghan man for alleged terrorist activity.
This week, authorities arrested a 19-year-old Jordanian manÎ¾for plotting to bomb a Dallas skyscraper.
Dennis Storemski, the City of Houston's Director of Public Safety and Homeland Security, says plots like these aren't anything new, but should serve as a reminder.
"I think as we move further from the World Trade Center event, I think it's human nature just to sort of let down your guard. But the reality is the threat has always been there. There are people out there who are wanting to do us harm."
In the Houston area, agencies train together and share information through an intelligence fusion center. Storemski says local and federal authorities have run a joint intelligence task force here since 1985.
"The goal and mission of homeland security is first of all to prevent, and if we're not able to prevent, then to be able to respond and recover. Obviously you want to prevent this kind of thing and you do that through investigation and intelligence operations."
Storemski says some of the best tools for intelligence gathering are the eyes and ears of the public.
"We continue to encourage the public to report suspicious activity. And I think there's plenty more individuals like that out there that are just waiting for either the means or the opportunity to pull something like that off."
Storemski says the fact that there hasn't been any terrorist activity here is testimony to the diligence of Houston's law enforcement community.
Laurie Johnson. KUHF-Houston Public Radio News.