Programmer or killer? It's very easy to make a mistake

A little distracted from the working rush and try to guess everyone!

“You return home at night through the park, where no one else walks apart from you anymore. Suddenly, someone called you from the back, you turn around and see an overgrown character with glasses.
Who is it? Maybe a programmer who couldn’t fall asleep that night from over-voltage, wrote 5,000 lines of code, and he just went out to get some air, take a sip of beer on the bench, relax his brain.
Or maybe this is a real serial killer, from which it will be difficult for you to hide if you do not guess his intentions as quickly as possible and do not make legs! "

The dough has its own tips. I wonder who knows the most important character?