Of course it would. But I don't think that is why LE wanted the phones so badly.
If they find DNA or fingerprints on the phones, it is not a very strong case without any other evidence. The defense is simply that the person found the phones picked them up and ditched them once they realized they didn't work. They have to be able to tie the phones to the crime of taking BL. They have to be tied to something found inside of that house.
If they already have fingerprints or DNA from inside of the house that doesn't belong, then they really don't need the phones.
It's like if somebody stole your car and you noticed they took a granola bar too. Finding the granola bar wrapper may not prove a thing. It really doesn't make a strong case. Whoever's fingerprints are on the granola bar wrapper just says that they found it on the side of the road and picked it up. If they already have fingerprints from inside of the car, then they don't really need the granola bar wrapper to prove that person was the thief. KWIM
MOO
ETA- I'm not even convinced that they haven't found the phones. . .the outside casings of the phones. I believe that they are looking for something more, something smaller, evidenced by LE going into the woods with those screens. What do they really want? Some kind of chip, a SIM, a memory card?