The following links to the video page for 'Condemned: Criminal Origins'--the fourth video is called 'forensic evidence,' you'll have to claim you're over 17 and then you'll get access to the video. It demonstrates how 'Condemned' tackles collecting evidence from a gameplay perspective.
Basically, you have a digital camera that somehow hi-lites significant evidence such as strangulation marks or fingerprints in a kind of neon green...meanwhile there are arrows that appear on four sides of the camera directing you where to go, (you can also zoom in and out). It's pretty intuitive, and when you frame up the shot appropriately the edges of the frame glow, you take the shot, and the integrated cut-scene commences as the information is transmitted to your contact in the lab who analyzes the evidence and via the radio/cell phone reports the results. Your next move is based on what she says.
The 'collect evidence' mini-game is triggered when you enter a space where evidence
exists--your collection tools replace your weapons as the conspicuous things you're
holding. This can be annoying if there are bad guys, in which case you have to return to the killing zone--where your weapons reappear--kick ass, and then return to the evidence zone. It can get frustrating in a fight when you accidentally step in and out of the 'evidence zone' because it's unclear where it begins and ends. Mercifully, when the bad guys are dead, you can focus more or less completely on collecting evidence, (though there's always an underlying sense something spooky or violent is about to happen).
(Condemned flash site--good trailers, etc.)
http://imdb.com/title/tt0496608/fullcredits#writers (game credits)
http://www.imdb.com/title/tt0780609/ (movie based on the game, 2008)