Can a police see a prior arrest if the case was dismissed and sealed?
If the case is officially expunged and completely taken off the record, then no one, including law enforcement, is able to ever see the arrest again.  However, if the case is only dismissed, then law enforcement will continue to have access.  If the case is "sealed," then law enforcement's access will depend on how the case was sealed and the parameters of the sealing.  Sometimes, law enforcement will still have some limited access.