You're not going to cop out at the last minute, are you?

你不是打算临阵脱逃吧？

These thieves had to cop out.

这些窃贼不得不向警察坦白服罪。

Answer: you cop out and buy the LOLcat book.

答案是：你会逃避并且买一本小猫咪图片的书。

That feels like a selfish, cowardly cop out to me.

在我看来这是自私的，懦弱的逃避。

The users cop out of them if they are not suitable.

警察在他们的用户了，如果他们不适合。