Opinions & Expert Testimony (701-706)

If lay witness is giving an opinion, what is that testimony limited to? (701)

1. Must be rationally based on their perception,

2. Must be helpful to clearly understanding their testimony or to determining a fact at issue, and

3. Must not be based on scientific/technical/specialized knowledge

**602 requires personal knowledge as well

What is the bright line rule distinguishing fact from opinion?

There isn’t one; facts are generally more specific/concrete and opinions are more general/conclusory

What is the collective facts doctrine?

If it is impossible/difficult to reproduce data observed by a witness/facts can’t be adequately described or presented, the witness may state their impressions or opinions based on their observations

Ex.: Opinion that D is the person in a video; Impression that victim underwent personality change and physical/emotional/educational performance had declined; the road crossing was in poor condition therefore it would be difficult to cross; D couldn’t get to work regularly because they were an alcoholic; it seemed P had time to get out of the way of a flying object

What must the proponent of an expert witness demonstrate to qualify the witness as an expert/allow for their testimony? (702)

It is more likely than not that expert’s specialized knowledge and opinion:

1. will help trier of fact understand issue or determine a fact at issue,

2. is based on sufficient facts or data,

3. is the product of reliable principles/methods, and

4. reflects a reliable application of the principles and methods to the facts of the case

What is the Frye test for allowing expert testimony?

Whether the methods used are “generally accepted” in the pertinent scientific community; made scientists the gatekeepers

What is the Daubert test for allowing expert testimony?

Judge assesses whether testimony is based on sufficient facts/data, is the product of reliable principles/methods, and the expert applied such methods reliably to the facts of the case; makes judge the gatekeeper

Is the Frye test or Daubert test codified in FRE?

Daubert

Who can be an expert? What is the key question here?

Traditional: doctors, scientists, etc

Skilled: bankers, landowners, a drug dealer = expert in drug packaging, prisoner can be expert in prison slang or tattoos

Key question = whether the jduge will certify a particular witness as an expert in a particular subject

How can a proponent lay foundation to qualify an expert?

1. Show witness has particular knowledge, skill, experience, training, or education

2. Show witness is relying on valid principles/techniques that have been applied appropriately

3. Show witness has something to offer that is useful for a jury

Can experts testify on hearsay or general knowledge?

Yes, if other experts would “reasonably rely” on such information

Can full-time professional expert witnesses be impeached based on their fees/general loyalty to one side?

Yes, possible grounds for bias

Is an expert’s opinion on an ultimate issue objectionable?

No, not just because it embraces an ultimate opinion

**ultimate issues = elements of crime, claim, defense, etc.

What is the Hinkley rule regarding expert testimony on a defendant’s mental state? (704)

Expert cannot state an opinion about whether the accused did or did not have a certain mental state or condition that constitutes an element of the crime or defense

Can an expert testify about the mental state of most people in a group?

Yes because it isn’t about a defendant’s mental state specifically

Does an expert have to first testify about the underlying facts/data to give an opinion on it? (705)

No, unless the court orders them to; may be required to disclose facts/data on cross

Can the court appoint experts itself? (706)

Yes, on its own or on a party’s motion; usually only for indigent parties