## Facts

- A truck owned by Henri Studios, Inc. was parked on the right shoulder of a Texas highway when Jesse Ballou drove his car into the truck’s rear.
- Ballou and his passenger, Leonard Herman Clay, died from the collision.
- The parties disputed whether the truck driver complied with Texas warning-device requirements for a vehicle parked on the shoulder.
- After the crash, a blood sample taken from Ballou was tested and reported a blood alcohol concentration (BAC) of 0.24%.
- In a motion in limine, the decedents’ survivors sought to exclude intoxication evidence, arguing the blood sample lacked an adequate chain of custody and that there was no corroborating evidence Ballou had been drinking.

## Issues

1. Whether the district court abused its discretion under Federal Rule of Evidence 403 by excluding the decedent driver’s BAC test as unfairly prejudicial due to alleged reliability concerns.
2. Whether chain-of-custody and testing challenges generally affect admissibility or instead go to the weight of the evidence for the jury.

## Decision

- The Fifth Circuit reversed the judgment and remanded for further proceedings.
- The court held the BAC test evidence was admissible and should not have been excluded under Rule 403.
- The court concluded the test had very high probative value on comparative negligence, and the risk of unfair prejudice did not substantially outweigh that value.
- The court held that alleged weaknesses in chain of custody and reliability were matters for cross-examination and competing proof, with the jury to determine the evidence’s weight.

## Legal Principles

- Under Federal Rule of Evidence 403, relevant evidence may be excluded only if its probative value is substantially outweighed by dangers such as unfair prejudice or confusion.
- Evidence is not “unfairly prejudicial” merely because it is strongly damaging; Rule 403 targets prejudice that invites irrational or improper decision-making.
- In a comparative-fault negligence case, intoxication evidence bearing directly on the driver’s responsibility can be central and highly probative.
- Once a prima facie foundation is laid for an item of scientific or physical evidence, chain-of-custody imperfections and reliability disputes ordinarily go to weight and credibility for the jury, not admissibility.

## Conclusion

The Fifth Circuit held that excluding a decedent driver’s 0.24% BAC test improperly curtailed relevant proof of comparative negligence: the evidence’s probative force was not substantially outweighed by unfair prejudice, and reliability objections were for the jury to assess.


Ballou v. Henri Studios, Inc., 656 F.2d 1147 (5th Cir. 1981)