Chambers v. Mississippi 410 U.S. 284, 93 S.Ct. 1038, 35 L.Ed.2d 297 (1973)
During a riot, a police officer named Liberty was shot and
killed. Chambers was arrested and charged with murder.
Chambers argued that Liberty had been shot by a guy named
McDonald.
Chambers had the testimony of two witnesses who claimed
to have seen McDonald shoot Liberty, a sworn confession written by
McDonald to Chamber's lawyer, and three witnesses who claimed that
McDonald told them he shot Liberty.
At trial, Chambers put McDonald on the witness stand to
swear to the validity of the out-of-court confession. However, McDonald
repudiated the confession and testified that he did not shoot Liberty.
At the time Mississippi did not have an exception to hearsay
for statements against penal interest. If they did, then McDonald's
confession could have been admitted under that exception.
Chambers attempted to cross-examine McDonald as an adverse
witness, but the Trial Judge refused to allow the cross examination.
The Trial Judge further refused to allow the testimony of the three
witnesses who claimed that McDonald told them he shot Liberty.
Under Mississippi State common law, a party may not
impeach their own witness.
Basically, since Chambers had called McDonald to the stand,
he could not present evidence that McDonald was lying.
The idea that a party is forbidden from impeaching their
own witness is known as the voucher rule, and it is based on the
presumption that a party who calls a witness vouches for their credibility.
Chambers was convicted of murder. He appealed.
The Mississippi Supreme Court affirmed. Chambers
appealed.
The US Supreme Court reversed and remanded for a new
trial.
The US Supreme Court found that the voucher rule
has its basis in ancient times, when witnesses were partisan and
routinely lied under oath. That has little relation to modern criminal
trials.
The Court found that the voucher rule clearly
violated Chambers' 6th Amendment right to defend
himself. Since there was insufficient due process, the case is remanded
for a new trial.
This case was decided under the common law. Today it
would be governed by FRE 607, which says that any party can attempt
to impeach the credibility of any witness.