State v. Matthew J. Knapp, 2003 WI 121, on certification
For Knapp: Robert G. LeBell
Issue: In essence, this court is presented with the question of whether a custodial inculpatory statement, obtained without proper Miranda warnings, and extracted through the use of police deception, is an “involuntary” self-incriminatory statement and inadmissible at trial for any purpose,” ¶95. (The police ruse involved inducing Knapp into talking by telling him that they were investigating constitutional violations committed by the department when they were in fact investigating Knapp’s involvement in a homicide.)
Holding: Given Knapp’s intelligence, awareness of his rights, the short duration of the questioning and the absence of any threats or promises, ¶¶104-05, his statement was voluntary. ¶¶108-09. Although the statement is inadmissible in the state’s case-in-chief because of a Miranda violation, because it is voluntary it may be used as impeachment. ¶111.
The court reaffirms that “evidence showing that a promise has been made by law enforcement officials does not, per se, require a finding that the induced statement was involuntary.” ¶109. Rather, a promise is considered along with other circumstances. Id. That said, a threat that the person will lose her children unless she “cooperates” is very likely to result in a finding of coercion — see, e.g., Lynum v. Illinois, 372 U.S. 528 (1963); McCalvin v. Yukins, ED MI 02-73447, 1/3/05.