I apologize if this has been asked/answered before.
Thanks to the X-com Files wiki I've been able to figure out why I still haven't been able to build laser weapons - it's because I haven't interrogated an alien engineer.
On what kind of missions does one typically encounter an engineer? As far as I can tell, they don't spawn on UFO crash sites or terror missions.
Do I have to raid an alien base to get my hands on one?
EDIT: I just started a raid on an alien base, and the very first alien I encountered and KO'ed was an engineer. Wish me luck!