arrest warrants are not good until they are carried out. An arrest warrant must be very specific on the person to be seized and where they will be seized (unless it is done under a police chase -- then no warrant is needed). Because you are dealing with 4th Amendment search and seizure rights, an arrest warrant is granted upon probable cause. If the arrest warrant's probable cause is too remote in time, meaning it happened months earlier, it may not be valid anymore. It depends on the circumstances.
The best thing to do is check under attorneypages.com to find a criminal law attorney or look under legal links under criminal law and you may find the information there.