Retired police dogs that Ive adopted?

They are such lovers... So loyal. Ive got two from san antonio texas... Drug sniffers, but though they are so adorable they have tendencies to snap at me bc of truama. Chuy and Sandy retired at age four and three. I had the k9 unit give me a lot of guidance and did research and my conclusion is it takes time and trust b4 they can truly relax. Any police officers that can offer advice about dogs that have served?