On Point blog, page 12 of 12
Expert Testimony – Mental Disorder – Usefulness to Fact-Finder
State v. John J. Watson, 227 Wis.2d 167, 595 N.W.2d 403 (1999), reversing unpublished decision
For Watson: Richard D. Martin, SPD, Milwaukee Appellate
Holding: Admissibility of a psychologist’s (preliminary hearing, 980 proceeding) testimony that Watson’s crime was sexually motivated is upheld:
¶ 52. … While the average lay person may be able to draw reasonable inferences from facts, an expert ought to be able to show how a person’s offense relates to the person’s purported mental disorder,
Expert Testimony – HGN test
State v. Rodney G. Zivcic, 229 Wis.2d 119, 598 N.W.2d 565 (Ct. App. 1999)
For Zivcic: John J. Carter
Holding: The trial court’s discretionary determination to admit expert testimony on the HGN sobriety test is upheld. In particular, specialized knowledge in the “underlying principles” of HGN testing isn’t necessary. All that’s required is expertise in administering and evaluating the test.
PBT – Requires Expert Testimony
State v. Kurt J. Doerr, 229 Wis.2d 616, 599 N.W.2d 897 (Ct. App. 1999)
For Doerr: John M. Carroll
Holding: A preliminary breath test (unlike certain other breath test instruments) requires expert testimony to explain its import:
The PBT device has not been approved by the DOT and does not receive a prima facie presumption of accuracy to establish a defendant’s blood alcohol level. Therefore,