Warrants are unrealistic due to the fact that they continue to be arrested and then released and so on.
Warrants should be made so that it is either:
a) A one time arrest for that warrant.
or
b) They continue to be in jail until they either have a court case, or if they pay bail. (most realistic)
Also I think warrants should only be issued for felonies or multiple misdomeanors. Usually in real life you would not get a warrant over a misdomeanor until after the court case has been done and a punishment was given.