brotherly love

The episode we watched yesterday was about two brothers and one killed the other brother because of money and familial problems. There was also a trucker who killed a bunch of women with his girlfriend. I think that in the brother killing, they linked him to the murder by glass that they found in the cuff of his pants to the window that he broke. They found out that it was the same glass by checking the density of the two. I thought that was very realistic and could find that it was matching glass. However I am going to challenge how they found that trucker. They used some sort of computer program and were just typing in variables which supposedly eliminated the truckers until they found the one that committed the killings. I dont think they could have actually done that to find someone who did the killing. They were typing in too precise variables.