Literally, one who is profficient in the tecktonik, however, it is often used to mean anyone who dresses in a gangster-like manner, yet isn't as cool as they "talk" themselves up to be. Put simply, a try-hard hip-hop bitch.
This particularly applies to people in France, and the surrounding area.
"Get a load of THAT Teckonik Killer"
"What a Tecktonik Killer"
"Here come the Tecktonik Killers!"