Ignorance or on purpose

Sometimes people do some things or say something out of ignorance and there are other times they do it on purpose. But sometimes it becomes hard to tell when it is ignorance or when it is on purpose but at other times, it is easy to guess if they are trying to escape responsibility by claiming ignorance of something but other times they purposely withhold something which should not be held otherwise. For example when some cop stops you for doing something illegal, you can show your innocent face and say that you did not know or are ignorant of what you have done but you rarely say that you did it on purpose because you have something urgent to do or just did not give a damn about the law or you thought you can get away with it. But as I said before if you have a bad reputation then even if you claim to be ignorant about something, people will believe that you have done something on purpose. But acknowledging about a deed depends upon what you have done and depending on that you can either plead ignorance of the issue or say that you did it on purpose for such and such reason. But this thing about whether to claim ignorance or on purpose does not always last and you may have to come out clean some time. But this thing you witness it all the time and even practice it too and it is not only confine to adults but also to kids which they weigh whether it will give them punishment or they can get away with something. So all in all you must weigh the pros and cons before you decide what to do in a particular situation.