I Can't Sense Their Presence

A Stock Phrase used by a Sensor Character. If used at the end of a fight, this is a convenient way of saying that someone is probably dead without any of the nasty gore. In other situations, it's an easy way to show that something is not quite right with a character; despite them being perfectly visible, they can't be detected by supernatural means. They might be Dead All Along, an Energy Being, or simply something other than human.

Related to Never Say "Die" and Disney Death. See Also I Sense a Disturbance In The Force. Compare Fainting Seer and Poke in the Third Eye.

Examples of I Can't Sense Their Presence include:

Anime & Manga

Used a lot in Dragon Ball Z, in part because of the fact that characters can hide their presence and in part because most characters have some form of sensing power.
- Used for the most drama at the beginning of the Android Saga. The heroes arrive at the city where Future Trunks predicted the androids would begin their rampage, but can't sense anything unusual. Yajirobe arrives, drops off some senzu beans, leaves in his sky-car - and gets blasted out of the air by the villains, with the heroes unable to even tell where the shot came from.
In Magical Record Lyrical Nanoha Force, when Tohma was taken over by his Black Knight form, Isis notes that she is no longer able to detect any magic from him nor read his thoughts; it was as though he was just a walking corpse.
In RG Veda, when no one can sense Ryu-ou's presence anymore.
In the Yu-Gi-Oh! 4Kids dub, Yami says this after Pegasus's Shadow Game finishes him. In the original Japanese version, there's no implication—it's straight out said that he's dead, even though he's not exactly so.

Comic Books

In most versions of Spider-Man, one of the things that makes Venom such a threat is that he doesn't trigger Peter's Spider Sense.

Film

In Serenity, River has a Level 11 Freak Out because she can't sense the thoughts of any of the Miranda colonists. Because Miranda is a Ghost Planet.

Literature

The Obsidian Trilogy: After the final battle, Vestakia notes that she can't sense her father, the Demon Prince any more, showing that he is finally dead.
In the Sword of Truth series, Adie, who sees solely using magic, is alarmed to discover that she is unable to see Richard's half-sister Jennsen, because she is one of the "pristinely ungifted".
Alice from Twilight can only see the futures of humans (which she has been) or vampires (which she is). Anything else is a blind spot to her, including Jacob and his pack, and Nessie, Bella's Half-Human Hybrid daughter.
In The Wheel of Time Aes Sedai bond Warders as a means of protection. This bond forms an empathic link between the two allowing them to sense the direction and distance to each other, as well as emotional and physical state. If either member of the bond dies, the loss is very noticeable to the other. An Aes Sedai will experience serious depression from the death of a Warder. The Warder will usually either die of shock or fly into a Roaring Rampage of Revenge.

Live Action TV

Leo from Charmed would often do this, especially when one of the sisters were missing.
On Star Trek: The Next Generation one Betazoid - who generally get their mind-reading powers at puberty but in his case they manifested when he was a baby, so he's been inundated with others' thoughts all his life & can't filter them out - is very pleasantly surprised when he can't hear Data's thoughts, since Data is an android.
Tracker has a version of this, but not because of death. Cole just had a harder time keying into his targets' life forces as they adapted more and more to Earth's environment.

Western Animation

In the Justice League pilot, J'onn J'onzz claims that he can't (telepathically) sense the presence of Batman anymore when the latter is apparently shot to death. It's a lie, obviously.
In Wolverine and the X-Men, Emma Frost can't find Jean Grey via Cerebro, leading nearly everyone to assume that she's dead. Turns out she's actually in a coma.
In the two-part opener of the X-Men animated series, Morph's death is indicated by having Jean Grey and Professor X unable to detect his mind via Cerebro.