The A-rated Kill Warrant scanner does indeed use an insane amount of juice just to look up a criminal record. No logic to it, as the lower rated scanners are still capable of doing the difficult bit [communicating across the galaxy to find the criminal records] and all the rating does is affect how close you need to be to the target. (kilometres versus tens of thousands of light years...)
Surely it should be just a software upgrade to your scanner and comms systems? But then - of course - it is a game and FDev have chosen the power mechanic and use of a utility slot as their favoured means of balance...
Pity it no longer doubles your bounties. I've removed all mine - as not justifying their ship resources. BUT when FDev release the proposed improvement, I may check them out again.