I think it's a case of "falling thru the cracks." Not enough of the left hand talking to the right hand. Look at the case of Jaycee Duggard. Law enforcement missed multiple chances of discovering her alive and imprisoned in her abductor's backyard. Sounds like law enforcement dropped the ball in the case you've mentioned also.
"Navywife".. It not so such much Law Enforcement..It those who are meant to be in CHARGE of these freaks that is messing the system up, Law Enforcement can only go out and arrest.The rest is left next to the Court system, then the next step is the ones who are to be making the home visits or looking at a file that of an Offender that is placed in front of them....
Some laws need to be changed, however that take funds and the people we elect to make the effort. Most just want to collect a check I feel...