You are unacquainted with the case details.
Efforts at "winging it" in the interview room or going on a "fishing
expedition" very rarely produces positive results. You should
always approach every interview with the "construction of proof"
as your objective. That's for all interviews - victims, witnesses,
suspects, applicants, informants, petitioners, etc.

You approach your subject with an assumption of guilt.
No one can be truly objective when they enter the interview room
but by assuming guilt, we typically ignore asking the questions or
hearing answers that might challenge and even threaten our pre-
conceptions.

You use an “accusatory style” interview.
An accusatory style tends to "drive" the interview in only one
direction and rarely uncovers new or additional information. It also
seldom generates cooperation from victims or witnesses and
compliance from subjects. An accusatory approach is also
notorious for generating contaminated statements.

You frequently interrupt your subject.
Any interview as well as an interrogation is far from being
successful without active, participatory listening by the interviewer.
Frequent interruption cuts off the flow of conversation and
ultimately information.

You are repetitive in your questioning or labor over the same line
of questioning.
Persistent questioning from a single narrow perspective tends to
frustrate even the cooperative subject - it tends to lock their
reasoning and thinking process into one line of thought. Varying
your approach, method of framing a question, and using a more
narrative-based approach results in content rich statements and
cooperative subjects.
Note: Once the interview starts out bad, it rarely ever improves.

© 2005 by Stan B. Walters "The Lie Guy®"

Author's Bio: 

Stan B. Walters runs the company Truth & Deception, Inc.
He works with agencies and organizations that want to train their
people how to conduct successful interviews and interrogations
and uncover the real story.
Stan@TheLieGuy.com
www.TheLieGuy.com
www.TheLieGuyBlog.com