Where were the police?

We're told the police investigated upon Logan's initial disappearance, but appear to have lost interest thereafter. You'd think that once he reappeared, someone would have had the good grace to inform them. One assumes they'd be interested, especially as the private detective Carter had been found murdered whilst searching for him - I'm assuming, of course, they knew about this connection. That a safe he'd designed had been expertly dismantled and emptied during his absence, would have given them even more reason.

My guess is the police weren't needed on a case where the crooks were so stupid. Why were they trying to murder Logan in the beginning on some open waste ground? Why would they park a registered car, one they'd already unsuccessfully used to try and run him down, across the road from his office? Why leave a loaded rifle in that cupboard? Why did Bruno come back at night to set up his sniper's position when Logan's office wouldn't be open for hours?