How to unlock PRO difficulty level?

[OmegaTreeFish]

basically when you complete the game on recruit or contrator any primary weapons you hadnt purchased become purchased. Complete it on pro and it buys the rest for you.

try just doing the last level again and see if that works.

[diudiu]

Finally it's unlocked.

After having completed the game at recruit level we first tried to play the last mission again. It didn't unlock the pro mode. Then we started playing at contractor level and played the first mission through (the one with training). Didn't unlock it. Then we just kept on playing and played the game through at recruit level. And then the pro difficulty was unlocked plus all primary weapons purchased.

And then we started again all over, pro level this time

Thanks for replies to all anyway.

[Sam]

Thats good to know.