AURORA, Colo. -- Neighbors of an Aurora man, arrested in a terrorism investigation, say they are shocked and relieved.

“I was just really surprised. It’s weird there would be a potential terrorist here in suburbia,” said Lauren Holter, who lives at the Saddle Rock Apartments.

A couple of her neighbors, Najibullah Zazi and his father Mohammed, were taken into custody late Saturday night. The arrests came about three days after local and federal authorities stormed their apartment, searching for clues in an alleged terror plot.

“My mom was worried there was a bomb planted somewhere, or something,” Holter said.

“I’m surprised he wasn’t arrested earlier, with all the interviewing they’ve done,” said another resident, Lynn Robertson.

It wasn’t what authorities found in the apartment, but what the men allegedly told investigators, that landed them in handcuffs. Specifically, officials say during three days of questioning, Najibullah lied about information found on his computer, including hand written instructions for making bombs.

“I knew him and never suspected anything. It’s kind of scary,” resident Brad Battung said.

He said he didn’t know Najibullah very well. Battung said the two exchanged “hellos” a few times, and talked briefly about Najibullah’s job as a shuttle driver at the airport.

With the Zazis now behind bars, residents are letting down their guard. A Sunday Broncos party at the apartment clubhouse brought neighbors together, and provided a chance to answer another important question:

“Who else could be living right next door to us? I’m definitely going to be more cautious about neighbors and get to know them better,” said Battung.

7News also tried to talk to Najibullah Zazi’s attorney, employer, and Aunt and Uncle on Sunday. None of them would comment about the recent arrests.

If convicted on the current charges of lying to investigators, the Zazis each face up to eight years in prison and a $250,000 fine.