Once again I think the anti EU camp (and there are plenty in it) are missing the point.
What is so wrong with a member state being able to insist another member state helps with their enquiries.
Picture this. Say the late Raoul Moat had been a Spaniard here on holiday and had killed a load of folk and then "disappeared". Would you object to The British Police demanding info from Spain? No didn't think so.
More tabloid rag sensationalism. If only they would do a proper expose on the real waste and cost of the EU.
I agree completely with your point concerning the staggering costs involved in keeping the Brussels machine up and running.

With regard to States helping others with enquires, I fear that this point holds much more complexity that is readily evident and goes far beyond one merely offering assistance to another in certain matters.
The European Criminal Bar Association (ECBA) has been looking at the ramifications of particular aspects of this proposal and has released several documents to illustrate its concerns;
At present, the ECBA rejects the replacement of the existing laws and rules on mutual assistance in criminal matters and on mutual recognition of evidence in criminal proceedings by a single instrument on the basis of the principle of mutual recognition, inter alia;
Mutual recognition of evidence in criminal proceedings presupposes in particular the existence of binding and enforceable safeguards regarding the collection and the use of evidence. The ECBA does not believe that a "single regulation" is feasible. There are major differences between different types of evidence. The national rules on Criminal Procedure ensure the legitimacy and integrity of evidence through different means and at different procedural stages. This results in serious problems for the transfer of evidence to another criminal jurisdiction. On the critical point of evidence gathering/preservation and dissemination, there is presently no homogenised framework that affords the simplified operation of such a proposal.
The attempt to create a single standard that ensures the integrity of the evidence in question is maintained at the highest possible standard will be exceedingly difficult to do. If this attempt were successful, I can foresee such challenges to the evidence tendered during the course of a trial being responsible for it being bogged down in protracted legal argument.
If an illustration were needed to highlight the potential conflict in standards with a local European constabulary investigating a scene and gathering the evidence from it, perhaps if we cast our mind back to the Madeline McCann disappearance in Portugal and the quality of the police investigation into it.
This is but one of many practical difficulties within this proposal and its potential adoption only suggests to me that the intention of ‘Brussels’ is to force through any legislation at all, whether well conceived or not, that is considered to be of benefit on the determined, yet myopic, road to the Euro super-state.