The police have no intention of letting anything get in the way of them when investigating crimes, even if there is no pressing reason to do an inspection quickly they will just press ahead without any regard to the chance of recovering money by selling the asset.
So in answer to your question the chances of getting an aircraft engineer to help in the search of an aircraft are almost nil, they will just rip the thing apart and sell it as scrap once the investigation is finnished.
I even know of a case where the police and airline security department installed video equipment in the cargo bay of an airliner without any input from the technical department of the airline. This of course was a totally unauthorised modification that breached a fireproof compartment. The practice was stopped only when the equipment was discovered during the troubleshooting of an unconnected system, and the technical department removed the unauthorised modification.