If the subatomic particles share a quantum entanglement with the other subatomic particles, and the universe is deterministic, then you could 'read' the states of all the entangled particles, and extrapolate backwards to a past state.
It's no more BS than warp drives and transporters.
Of course, I really doubt the writers thought of that, or the implications of such a scanner, they just needed to move the plot along, and were too lazy to write any forensic/detective work.
One particle shares a quantum entanglement with another particle, which shares the same with the first particle, it's one to one. Quantum also postulates that you can know only one thing about a particle, either it's position, speed or direction.
Now lets talk about a molecule, lets say it's from strong female character, so it's carbon based human molecule, since the biggest organ in a human is the skin we'll say it's a skin molecule. since we're mostly water we'll say it's water from a skin cell. So it's h2o.
How many particles are in ONE water molecule? It depends what you mean by particles. Water (H2O) is, of course, made up of two hydrogen atoms and one oxygen atom. Each hydrogen atom is made up of one proton and one electron. An oxygen atom is made up of 8 protons, 8 neutrons and 8 electrons. Neutrons and protons are classified as hadrons, subatomic particles that are subject to the strong force and as baryons since they are composed of three quarks. And so it goes on.
So it's got 2 proton and 2 electron from the hydrogen
and 16 protons, electrons and neutrons from the oxygen
Total particles : 52
Let's be generous and multiply all that by 3 (quarks)
52X3= 156 quarks.
Now let's say each of those is entangled with another from the same exact body you now got 156X2 = 312 quarks.
How many quarks do you guess the human body contains?
And you're disregarding that you can only know one thing about a particle. and that the molecule comes from one body, how do you reconstruct the whole scene? It's homeopathic Forensics, one molecule contains all the "info" of the other billions of molecules and since it was in contact with the other bodies it contains all the info from those bodies too.
Nope, no way you can sell me on that.
A Warp Drive Is Theoretically PossibleTheoretically Teleportation IS Possible