Mechanisms in kinetic reactions
As far as I know, the short answer is no; in general, it is not possible to know the reaction mechanism a priori.

In general, the approach is: 


Postulate a reaction mechanism/pathway 
Use this to calculate the relevant reaction rate(s)
Compare these rate expressions with the results of experiments


If your proposed reaction mechanism matches the empirical results, it is likely (but you can never be sure!) that the mechanism is correct. If not, a new mechanism should be postulated and tested.  

That being said, in many examples it may be possible to make an educated guess of a plausible reaction mechanism - based on your own experience or the experience of others (i.e. from articles etc.) - and then investigate whether the proposed mechanism matches the empirical facts of relevant experiments. Often, the proposed mechanism is more or less correct. 

In addition, modern advances in computational chemistry may give useful information regarding likely reaction pathways based on the structure and interaction of the involved molecules. To my knowledge, it is not yet possible to use this in a standalone fashion to figure out the detailed mechanism, but it may help out in terms of making a better educated guess.