are you crawling? first hide near the guy working on the truck and let the guard start walking away before you move out. you can then hide behind the next building over, then crawl across the compound and hide in the grass between the two buildings (careful, i seem to recall there's a guy in there somewhere), from there you can get started crawling right after the guard passes and get over to the bushes near the building where the officer is. it's all timing and patience my friend (and a few save game reloads!
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