At a minimum they testified to what they saw and heard. That's one or more.
Let me expand on this since I have more time.
Federal rule 602 and its associated notes and case law requires an eyewitness to have perceived an actual external reality with their organic senses. The law distinguishes between internal mental states and external observed reality. Experiences such as dreams, hallucinations, and near-death experiences are internal mental states even though they manifest as recollections of sensory experiences. A witness recounting a near-death experience may state their knowledge
that they had the experience. But they do not have legally required knowledge
of the events purported in the experience. This is an ironclad legal distinction in American law.
During
voir dire of an eyewitness (the few questions at the beginning where the qualification of the witness is presented to the trier of fact), the witness will be asked under what circumstances they had knowledge of the things they are about to recount. They will need to state their physical circumstances. Let me stress this: you need a
physical opportunity to observe what you're about to testify to.
Veridical NDEs may possibly qualify. These are the kind where the witness is able to recount precise, verifiable details about their circumstances, such as laying in a hospital bed while clinically dead and being able to recall verbatim a conversation between other people in the room. Because those are tied to a plausible physical opportunity for sensation (even if others think you're dead), it can qualify under Rule 602. You would still have to endure a blistering cross examination, but such testimony would be admissible initially.
What isn't admissible are the purely experiential kinds of NDE that are commonly proffered as evidence for an afterlife, not just continued existence "after death" in the known physical surroundings of the claimant's body. I gave examples of that before, such as seeing a light and heading toward it, having your life flash before your eyes, seeing loved ones, experience a euphoric feeling, seeing idyllic scenes. These fail admissibility under Rule 602 because the description of your
physical state is something along the lines of laying on a hospital bed with your eyes closed and otherwise unresponsive to sensory stimulus, and lacking organic function sufficient to receive and process sensation.
The "matter in question" is what's important. If the matter in question is the appearance of your long-dead Uncle Bob standing in a beautiful green field, then the purported physicality of that claim has to match the observable physicality of your situation. No, your physical sensory organs are not anywhere near a putatively physical beautiful green field and they aren't seeing your dead uncle. They're in a hospital bed in a treatment room, mostly inert. That's the external reality. If what you experience cannot even find a nexus to an actual, sensible, external, physical reality, then the law treats that as an "all in your head" situation and you won't qualify under Rule 602. Even if your senses were still somehow operating, there is no physical opportunity to see green fields in a hospital room, or a dead person. The nature of the claim is incompatible with the
physical circumstances to which you are subject.
This is obviously different than the veridical NDE. If your senses were somehow still operating, the claims in a veridical NDE are at least plausibly compatible with the
physical reality in which your body finds itself. You claim to hear a conversation taking place between people in a hospital room—while you're lying dead in the bed in the hospital room. That's the nexus between what you say you experienced and an external reality.
I'm picking on you like this because claims of what is legally admissible are often fun to make for rhetorical effect, but usually run up against what actual legal findings are. So unless you know something about the actual law, it's best not to embellish along those lines. Courts really have heard it all: claims about theory-of-mind and epistemological handwaving that you can get away with informally elsewhere. They don't buy it. If in your NDE you claim to be heading toward a pleasant white light, that's admissible as eyewitness testimony only if you can prove that your physical circumstances produced the opportunity for actual photons from such a light to be actually hitting your actual retinas. The law
really wants what is claimed to be eyewitness testimony to be something that's actually physically experienced via the senses.
