Academic institutions generally don't teach people to code. It's always a personal quest. You can tell a lot about somebody who's graduated but never gone any extra mile. That should be the basic filtering criteria.
I too have seen people studying at CS departments who were useless at coding. I even helped some mates with their assignments so that they wouldn't get thrown out having invested several years already, though our field of study was not purely CS but more the hardware side of things so graduating as a bad programmer wouldn't be a terribly bad thing. Yet I know for certain none of them ever planned to be looking for a job as a programmer. And if you investigated their programming accomplishments you would quickly find out they should be passed on.
I also noticed that people who are smart and even brilliant do graduate with real programming skills but without personal projects of any sort. The thing is, they may join in as an ordinary programmer but do not plan to stay there long, meaning to quickly move into management or a business branch. You probably don't want them either.
Some preliminary research is always the right thing to do. You won't believe how many times I arrived at an interview and watched the HR turn over my resume to the interviewer for the first time ever, so he had to quickly scan it to get an idea what to discuss. With that approach not much can be accomplished on the hiring track.