The sites were first identified by cadaver dogs, and testing equipment had shown the possible presence of remains, police said.

Can I replace cadaver dogs with search dogs without change in meaning?

Not without changing the meaning.

Some dogs are trained to follow a scent. Some are trained to find live people. Some are trained to find drugs. All of them serach in in capacity.

As gruesome as it sounds, I believe some dogs are trained to find dead bodies - and although they may also be used for live people, if they are being referred to as "cadaver dogs" then that's what they were trained for. I remember reading a story about the search and rescue dogs who were showing signs of depression after 9/11 because they were finding only dead bodies.
Thanks, GG. I didn't know search dogs were trained in different areas. I thought they were able to search for anything their owner showed or provided them. Silly me. Thanks!