[LibertyRocks]

In one of the first articles or video reports I saw regarding the arrest/questioning of the students stated that they were showed up at the apartment building AFTER the blast and apprehended Cheema AFTER he came out of an apartment in the building. It was then that they took into custody the others in the apartment he came out of.

Another article/video mentioned that they found a wallet on the body - hence how they were able to know where to look so quickly...

Here's an excerpt of one article discussing the arrest/questioning:

Student recounts talk with worker - FR Thread
Hinrichs' roommate was Fazil Cheema, a student from Pakistan. Law enforcement officials late Saturday came to the Parkview Apartments complex where the pair lived, located Cheema at a neighboring apartment, then interviewed him and about a half-dozen others, who are Muslims. However, spokesmen for the local Muslim community say Cheema himself is not a practicing Muslim.

< SNIP >

Hinrichs and Cheema lived in a nearby unit, and Cheema was at the neighboring apartment when police arrived.

[Cicero]

I guess you would need to know whether it took a few minutes, 15 minutes, half an hour, who knows? The normal police response would be to visit Kinrich's room, search it for evidence, interview his roommate and friends, and so forth. But if it were done in the normal course of an investigation, it would probably take more time than if the whole circle were suspected of being terrorists and were being watched.

I don't know what the timeline was. We have only one student's suspicions to raise these questions. But the news media ought to be doing some investigating, even though they seem to have lost the habit of actually digging up facts.