Complex sentence: The son (Sam Raimi) gets everything because he's in the will while the detective (Scott Spiegel) is trying to find out who murdered the uncle, while trying to avoid ending up dead as well.
Split into simpler sentences: The son (Sam Raimi) gets everything because he's in the will. The detective (Scott Spiegel) is trying to find out who murdered the uncle, while trying to avoid ending up dead as well.