randi kaye looks at how it works and who's riled up about it. >> reporter: what you're looking at is a federal crime. this is a gun show. and that man is selling a gun. no questions asked, no background check. >> reporter: this is undercover video from sharonville, ohio, part of a nationwide investigation to expose what's wrong with what's known as the gun show loophole. unlike licensed dealers, the so-called gun show loophole allows unlicensed private sellers to sell guns without doing background checks on buyers. they're viewed as collectors who are occasional sellers so they fly under the radar. but, this is key -- while they're exempt from background checks, it is illegal for private sellers to sell guns to anyone they know or have reason to believe would not pass a background check, which is exactly what some are caught doing on this video. why should you care? the bureau of alcohol and tobacco and fire arms says one in every three guns used in illegal gun trafficking is connected to a gun show. >> this is real -- this translates to people getting killed. children, adults, polic

randi kaye explains. >> reporter: this is the question. is texas governor rick perry a republican in a tough re-election fight trying to cover up the execution of an innocent man on his watch? >> this is a clear case of the governor sabotaging a public agency in order to cover up the findings for his own political advantage. >> reporter: here's what happened friday morning. the texas forensic science commission was supposed to hear the latest findings on what will really happened in the small town of corsicana, texas, nearly 18 years ago, in 1991. still in question because the original investigators said an arson fire killed three baby girls. it took a jury less than an hour to convict their father of arson homicide. but since then, three forensic investigations found there was no evidence of arson, none. >> reporter: one of those reports even came before cameron todd willingham was executed. still, the governor stands by his decision. friday, for the first time, the state's own hand-picked expert was to present a scathing report that show

randi kaye explains. >> reporter: this is the question. is texas governor rick perry, a republican in a tough re-election fight, trying to cover up the execution of an innocent man on his watch? >> this is a clear case of the governor sabotaging a public agency in order to cover up the findings for his own political advantage. >> reporter: here's what happened friday morning. the texas forensic science commission was supposed to hear the latest findings on what really happened in the small town of core si can in a, texas nearly 18 years ago in 1991. still a question because the original investigation get a tore said an arson fire killed three baby girls. it took a jury less than an hour to convict their father of arson homicide. but since then, three forensic investigationses found there was no evidence of arson. none. one of those reports even came before cameron todd willingham was executed. still the governor stands by his decision. friday for the first time, the state's own hand picked expert was to present a scathing report that showe