Somone claimed my son on their taxes. I know it wont his father hes in jail how do I file him for last year and this year. Because they rejected my taxes

[Anonymous]

if someone already claimed him all that can be done is to paper file. 

there should not be a problem in e-filing his return as long as it's mark the he an be claimed as a dependent.  if this is not true then his return will also have to be paper filed

what will happen is that the IRS will eventually send you and the other claimant a letter asking for proof your entitle to claim your son.   the letter will contain items you can submit as proof.   the one with the better proof gets him as a dependent.