MBE Rules · Criminal Procedure

Fruit of the poisonous tree

Wong Sun

The rule

Evidence derived from a constitutional violation is generally also excluded. Exceptions: (1) independent source, (2) inevitable discovery (Nix), (3) attenuation of the taint (free will of the defendant, time, intervening circumstances).

In plain English

If the police gather evidence illegally, anything they find because of that evidence is usually not allowed in court. But there are exceptions if the evidence would have been found anyway or if time and events break the connection.

Worked example

Officer A illegally searches a car and finds a map leading to stolen goods. Later, a witness independently tells the police about the goods' location. The map is excluded, but the goods can be used because of the witness.

Memory hook

Bad tree, bad fruit. Evidence from a rights violation is tainted unless exceptions apply: independent source, inevitable discovery, or attenuation.

The trap

Students think: Any evidence linked to a violation is out. Wrong, because exceptions can cleanse the taint. The actual test is whether an exception like attenuation applies.

How examiners test it

The MBE loves: illegal search leads to new evidence. Trap: students exclude all evidence. Look for exceptions like attenuation (e.g., long time lapse, intervening acts) to admit evidence.

Drill this rule until it can't fail you.

Vrenberg generates unlimited questions on this exact rule, tracks your mastery of it, and brings it back until it sticks.