Police attempt to rationalize their two-hour delay

From The New York Times:

And new information emerged that may help explain a fateful two-hour delay by university officials in warning the campus of a gunman at large. According to search warrants and statements from the police, campus investigators had been busy pursuing what appears to have been a fruitless lead in the first of two shooting episodes Monday.

After two people, Emily Jane Hilscher, a freshman, and Ryan Clark, the resident adviser whose room was nearby in the dormitory, were shot dead, the campus police began searching for Karl D. Thornhill, who was described in Internet memorials as Ms. Hilscher’s boyfriend.

According to a search warrant filed by the police, Ms. Hilscher’s roommate had told the police that Mr. Thornhill, a student at nearby Radford University, had guns at his town house. The roommate told the police that she had recently been at a shooting range with Mr. Thornhill, the affidavit said, leading the police to believe he may have been the gunman.

But as they were questioning Mr. Thornhill, reports of widespread shooting at Norris Hall came in, making it clear that they had not contained the threat on campus. Mr. Thornhill was not arrested, although he continues to be an important witness in the case, the police said.

Most murders are committed by people who know the victim. The closer the relationship the better the suspect. If a man is murdered the first person the cops will look at is his wife; if a woman is killed like Emily Hilscher the first person the police will suspect, in the absence of compelling information to the contrary, will be her boyfriend.

Yet it isn't written in stone and police should never close off other areas of inquiry especially when a murderer is at large in an area as densely populated as a large college campus. Yet that is exactly what police did when they heard that Ms. Hilscher's boyfriend owned guns. All other potential theories of what may have happened flew out of their minds and they homed in on Mr. Thornhill with single-minded determination.

Was their decision to ignore the possibility that a shooter could be lose on the Virginia Tech campus and focus on Mr. Thornhill, a decision which may have allowed the gunman to murder 30 additional people, due - at least in part - to anti-gun owner bigotry on the part of investigators?

Would some or all of those dead people be alive today if the police had not had a "well he owns guns so he must have done it" mentality?