I also think they do know who the 2nd suspect is, have probably talked to him, and as previously mentioned, probably is being watched. So LE isn't lying when they say he hasn't been named or arrested, because he hasn't but that doesn't mean they don't know who and where he is. Let him get cocky and do something dumb and LE will be all over it.
Also for those complaining about the search warrants and the time it's taking to obtain them, remember they are dealing with a suspect who has a lot of money and resources financially behind him. They don't want to make any mistakes in the case because they will be dealing with very good effective defence lawyers in court and they want to make sure every proper step is taken in collecting any and all evidence. You should be patient, they are doing it for Tim's sake. If they can't bring him home, his family would at least want justice.