Brick

Conventions - Dead body in a stream with a person watching it in distress. It appears to be a flashback of a memory.

Camera - Extreme closeup shot of both characters in scene emphasizing and intensifying the atmosphere of whats happened.

Editing - Editing is very slow, mainly to set the scene of the current circumstances.

Sound - Sound/music is slow with a sad effect which is suddenly interrupted by school bell.

Mise-en-scene - Stream, dead body partly within the stream. Another character watching in the short distance demonstrates his saddness and anxiety over the situation, can't believe what has happened.