Police really don't need any help, especially if it is the boyfriend. He has been interviewed by police, and even after that he was named a POI, so that tells me that his story either wasn't convincing or it was full of holes. Police will be looking in to his cell records and bank records in an effort to prove, or disprove his whereabouts at crucial periods in time. They'll be taking his vehicle and doing forensic testing. If it becomes very obvious that this guy was involved, they'll arrest him, but there is no hurry on their part. If he is truly a suspect, they'll be following him around, you can be sure of that.