Once someone is arrested, they have a right to a speedy trial. This length of time between the crimes and now (even longer) without an arrest (except Wint) is not unusual even when LE has a very good idea of who is guilty. IMHO, they already have enough on Wint, and he was dangerous enough, AND a flight risk so they brought him in right away. Others may not be as much of a concern and/or there may be less evidence so there may be an attempt to gather more. We've been admonished to stay on-topic, but there are numerous examples upthread of cases in which the time between crime/when the person came under suspicion and arrest is much longer than 7-8 weeks. In fact, I would venture a guess that it usually takes even longer than this to make an arrest in cases that don't involve a family member (e.g., husband killing wife). Thus, some of us believe that the length of time alone isn't evidence of a single perpetrator.