Photoshop Filter of Evil

"Just listen to the music, Marge! He's evil!"

—Homer Simpson, The Simpsons

Photoshop Filter of Evil is a trope about when a news program and/or documentary shows a photo of a criminal/victim in color, then shows a eerie black and white negative of the photo to emphasize something malevolent about the person. You'll also hear a sound effect as the photo switches filters, like someone is throwing the giant "make negative" lever. Usually something like a giant clunk, followed by the sound of rusty nails on a blackboard.

Film

Used for horror in film in Ringu, as it happens every time somebody dies by a stare-down with Sadako.

Literature

Parodied in Dave Barry Hits Below the Beltway, where two political candidates running against each other each show their opponent in hideous and increasingly libelous grainy black-and-white photographs.

Live-Action TV

People that Stephen Colbert has decided are "destroying America" often get this treatment.
An early episode of The Chaser's War on Everything has the group lampshading and spoofing this trope by using the same technique on the Australian PM. Hilarity Ensues.

Vdeo Games

In Plumbers Don't Wear Ties, the developers apparently just got Photoshop and were playing with it while making the game. The result: Tons of filtered photos in ridiculously random places.
The Yarudora series uses this trope a few times in several of its games.
- Double Cast, the 1st game, uses it during a sequence of the Genocide Route, when the protagonist and Haruka discover Shoko's body in her bathtub, and confirm, to their horror, her death;
- Sampaguita, the 3rd game, uses it on two occasions:
  - On the game's box cover, although it's done to symbolize the mystery behind Maria and her memories, as she's not evil.
  - And during the game, when the protagonist gets fatally shot while protecting his lover Maria with his body, in Good End 3 and Normal End 2.

Web Comics

Parodied by The Non-Adventures of Wonderella here.
A minor Easter Egg from Homestuck features a wacky (mildly crude) sound clip of Nicolas Cage from Snake Eyes with transformations making it into something a bit... disturbing. The visual accompaniment uses an effect much like this, except it's not a photonegative (rather, the image's color is distorted and JPEG artifacts become exaggerated). "boner!"

Web Original

Used on Original Bubs in Homestar Runner, in the sbemail original. It goes greyscale, too.
Lampshaded in an episode of Strong Bad's Cool Game for Attractive People, when Strong Bad is watching a marathon of rockumentaries, he stated "Uh-oh, they're using that negative photo effect; somebody's going to rehab."

Real Life

Elizabeth Short, The Black Dahlia, has had this done to her photo quite often on documentaries. It's usually meant to add chilling eeriness, emphasizing the way she was gruesomely murdered and severed. It's not applied to the actual crime scene photos, mind you, but her vanity head shot.
The History Channel lives, breathes, and eats this trope. Monster Quest has had a reenacted first wild hog perspective attack or three, where the post-production crew apparently felt little shame applying a desaturation filter and jarring piano chords. Ice Road Truckers even does this for accidents or ice cracks.
Notorious example: TIME Magazine did the desaturation and edge burn bit on a photograph of O.J. Simpson, in addition to resizing and moving the man's prisoner ID number. The resulting image made O.J. Simpson's skin appear darker and gave a heavy vignette. The manipulation became extremely obvious when Newsweek used the same photo with accurate color, resulting in a side-by-side comparison when the two magazines were displayed together at newsstands. This was met with significant outcry. TIME would eventually issue an apology for the cover.
- A variant is the Fox News Channel showing obviously altered photos of New York Times reporters they accused of being "attack dogs".
Martin Bryant, perpetrator of the Port Arthur Massacre, was represented in the media with a picture that had been digitally altered to look like an Evil Albino. One would think the fact he murdered 35 people would be enough to turn the public against him...
A popular variant on Australian tabloid television is to slow footage to ~6 frames/second.
The method is Older Than Radio, though was used not as a trope, but as a prank. R.W.Wood once asked a young lady to pose for a photo to be printed in Encyclopædia Brittanica article he was writing. She was flattered, but had no idea he's the trailblazer of IR and UV photography, the article is about fluorescence, and her photo is going to look like this.
The Wii has this filter in the Photo Channel.