First, there's no concealing evidence unless there's A) a duty to disclose, i.e., you just axe murdered a bunch of people... and then hid the axe. You defended yourself and take away nothing but COPIES of INFORMATION in the form of photos and verbally recorded affidavits. It's all still there, undisturbed for the authorities to collect copies of all over again, nothing concealled.
B) the police know about it or would reasonably be expected to uncover it, i.e., if you just defended yourself with a firearm and your wife takes said firearm away from the scene. It's a fait accompli that the police would know there was a firearm owned by you involved when you claim self defense. Then you've concealled evidence of a crime. The crime being the attack upon you by the decedent. If the police do not, and cannot know of your photographs or tape recorded affidavit, then there's no concealment.
C) if they ask for it and you don't produce it, i.e., you turned the evidence over to your wife. Your wife turned it over to your attorney. You're attorney refuses to turn it over to the DA, then your attorney would be guilty of concealling evidence because the police know about, asked for it, and you ... they didn't pony it up.
Now, if there was evidence like GSR on the decedent's shirt, which you removed by laundering it at the laundromat around the corner (love those response times) before putting it back on the corpse, then, again, you've concealled evidence because the crime lab would reasonably be expected to detect it if it were left there, even if there would be next to no way, in this outlandish example, for them to detect the concealment, assuming the shirt was thick enough that the flesh was not stippled underneath.
When they "Nudge. Shove. Shoot.",
Don't retreat. Just reload.