Title: State v. Peter Kienitz

State: wisconsin

Issuer: Wisconsin Supreme Court

Document:

SUPREME COURT OF WISCONSIN 
 
 
Case No.: 
97-1460 
 
 
Complete Title 
of Case: 
 
 
In re the Commitment of Peter Kienitz: 
 
State of Wisconsin,  
 
Plaintiff-Respondent, 
 
v. 
Peter Kienitz,  
 
Defendant-Appellant-Petitioner.  
 
ON REVIEW OF A DECISION OF THE COURT OF APPEALS 
Reported at:  221 Wis. 2d 275, 585 N.W.2d 609 
 
 
 
(Ct. App. 1998-Published) 
 
 
Opinion Filed: 
July 2, 1999 
Submitted on Briefs: 
 
Oral Argument: 
May 4, 1999 
 
 
Source of APPEAL 
 
COURT: 
Circuit 
 
COUNTY: 
Dane 
 
JUDGE: 
Sarah O’Brien 
 
 
JUSTICES: 
 
Concurred: 
 
 
Dissented: 
 
 
Not Participating: Prosser, J., did not participate. 
 
 
ATTORNEYS: 
For the defendant-appellant-petitioner there were 
briefs by Suzanne Hagopian and Mary E. Waitrovich, assistant 
state public defenders and oral argument by Mary E. Waitrovich. 
 
 
For the defendant-appellant-petitioner the cause 
was argued by Marguerite M. Moeller, assistant attorney general, 
with whom on the brief was James E. Doyle, attorney general. 
 
No. 97-1460 
 
1 
 
NOTICE 
This opinion is subject to further editing and 
modification.  The final version will appear in 
the bound volume of the official reports. 
 
 
No. 97-1460 
 
STATE OF WISCONSIN               :        
        
 
 
 
 
IN SUPREME COURT 
 
 
In re the Commitment of Peter Kienitz: 
 
State of Wisconsin,  
 
          Plaintiff-Respondent, 
 
     v. 
 
Peter Kienitz,  
 
          Defendant-Appellant-Petitioner.  
FILED 
 
JUL 2, 1999 
 
Marilyn L. Graves 
Clerk of Supreme Court 
Madison, WI 
 
 
 
 
 
REVIEW of a decision of the Court of Appeals.  Affirmed. 
¶1 
JON P. WILCOX, J.  The petitioner, Peter Kienitz, 
seeks review of a published decision of the court of appeals, 
State v. Kienitz, 221 Wis. 2d 275, 585 N.W.2d 609 (Ct. App. 
1998), which upheld a dispositional order of the Circuit Court 
for Dane County, the Honorable Sarah B. O’Brien.  The circuit 
court found Kienitz to be a sexually violent person under Wis. 
Stat. ch. § 980 (1993-94),1 and ordered his commitment.   
¶2 
The issues presented on appeal to this court are: (1) 
how should the term “substantially probable” be defined in Wis. 
Stat. ch. 980; (2) does the failure to define “substantially 
probable” violate Kienitz’s right to equal protection, (3) or 
                     
1 Wisconsin Stat. ch. 980 was created by 1995 Wis. Act 479, 
§ 40, and became effective on June 2, 1994. All references are 
to the 1993-94 version of the statutes, as amended, unless 
otherwise noted. 
No. 97-1460 
 
2 
render ch. 980 unconstitutionally vague; (4) what is the 
appropriate standard to review whether evidence is sufficient to 
sustain a commitment order; (5) based on the expert testimony 
presented, was there sufficient evidence to establish that there 
was a “substantial probability” that Kienitz would engage in 
future acts of sexual violence; and (6) if the evidence was 
sufficient, is ch. 980 unconstitutional as applied to him.  Our 
decision on the first four issues is governed by the opinion 
issued today in the companion case, State v. Curiel, No. 97-1337 
(Wis. S. Ct. July 2, 1999).2  This opinion answers the remaining 
questions.   
¶3 
We find that the evidence before the circuit court was 
sufficient to establish beyond a reasonable doubt that it was 
“much more likely than not” that Kienitz would engage in acts of 
sexual violence.  We further hold that Wis. Stat. ch. 980 is 
constitutional as applied to him. We affirm the decision of the 
court of appeals.  
I. 
¶4 
The evidence in the record shows that Kienitz has a 
long history of sexual violence.  In November 1963, he was 
                     
2 In State v. Curiel, 97-1337 (Wis. S. Ct. July 2, 1999), we 
held that the standard by which to determine whether it is 
substantially probable that a person will engage in future acts 
of sexual violence is whether the likelihood is “much more 
likely than not.”  This standard does not violate the guarantees 
of equal protection, nor is it void for vagueness. Id., op at 
31.  We further held that the standard of review applicable to 
criminal trials is also appropriate for sufficiency of the 
evidence questions in Wis. Stat. ch. 980 proceedings.  Id., op. 
at 27. 
No. 97-1460 
 
3 
convicted of indecent behavior with a child and sentenced to 10 
years probation with psychiatric treatment.  In 1966, he was 
found to be in violation of the terms of his probation by 
molesting young boys and was sentenced to an indefinite term in 
the Wisconsin State Prison system.  He was released in 1973. 
¶5 
In November 1977, Kienitz was found to be tying up 
young boys, including an 11-year old, tickling them, and 
fondling their penises.  He was convicted of first-degree sexual 
assault.3  Kienitz was sentenced in February 1978, committed to 
the Department of Health and Social Services under Wis. Stat. 
§ 975.06(2)(1976), and placed on five years probation.  
¶6 
Kienitz’s probation was revoked in September 1980, 
after he was arrested for sexually assaulting two boys.  
According to the complaint, Kienitz approached the two 13-year 
old boys in a park, tied them to a tree, pulled their shorts 
over their heads, fondled their penises for about one minute, 
but then untied them when they repeatedly asked him to.  Kienitz 
pled no contest to one count of second-degree sexual assault,4 
was sentenced to an indeterminate term of not more than eight 
                     
3 Seven additional counts along with the repeater status 
were dropped per the plea agreement.  
4 The criminal complaint alleged eight separate offenses 
ranging 
from 
second-degree 
sexual 
assault, 
and 
unlawful 
restraint of two 13-year old boys; intent to commit a crime 
against sexual morality involving two 10-year old boys, and 
unlawful restraint and intent to commit a crime against sexual 
morality involving one 12-year old boy.  Kienitz pled no contest 
to one count of second-degree sexual assault.  The parties do 
not dispute that this conviction was for a “sexually violent 
offense” under Wis. Stat. § 980.01(6). 
No. 97-1460 
 
4 
years in prison, and was ordered to immediate treatment at the 
Mendota Mental Health Institute (Mendota).   
¶7 
Kienitz was conditionally released from Mendota in 
March 1988, but one month later, his supervision was revoked due 
to seven instances of violations of conditions of his parole.  
Kienitz was returned to Mendota with a mandatory release date of 
October 4, 1995.   
¶8 
On October 2, 1995, the State filed a petition 
alleging that Kienitz was a sexually violent person eligible for 
commitment under Wis. Stat. ch. 980.  Kienitz waived his right 
to a jury trial, and a trial to the court was held.5 
¶9 
The only disputed issue at trial was whether there was 
a substantial probability that Kienitz would engage in future 
                     
5 Initially, the circuit court dismissed the State’s 
petition, 
concluding 
that 
Wis. 
Stat. 
ch. 
980 
was 
unconstitutional.  The State appealed.  While on appeal, State 
v. Carpenter, 197 Wis. 2d 252, 541 N.W.2d 105 (1995) and State 
v. Post, 197 Wis. 2d 279, 541 N.W.2d 115 (1995) were released 
upholding ch. 980 against the constitutional challenges.  The 
court of appeals summarily reversed the circuit court’s decision 
and remanded for further proceedings.   
No. 97-1460 
 
5 
acts of sexual violence.6  At trial, testimony was taken from a 
number of lay and expert witnesses.7   
¶10 The State presented two expert witnesses, Donald 
Irwin, Ph.D., director of psychology at Winnebago Mental Health 
Institute, and Ronald Sindberg, Ph.D, a psychologist at Mendota. 
 The defense presented Michael Caldwell, Ph.D., a psychologist 
employed at Mendota, as its expert.  All three reviewed 
Kienitz’s correctional, psychiatric and institutional records; 
Kienitz only allowed Dr. Caldwell to interview him.  The experts 
agreed that Kienitz had the mental disorder of pedophilia with 
the state’s experts testifying that the mental disorder creates 
a substantial probability that Kienitz will engage in future 
acts of sexual violence.  Dr. Caldwell placed his chances of 
recidivism at 48%.  
¶11 In determining substantial probability of future acts 
of sexual violence, Dr. Irwin defined “substantially probable” 
to mean “more than more likely than not.”  He testified that it 
was his opinion that Kienitz’s mental disorder creates a 
                     
6 In a commitment trial, the State has the burden of proving 
beyond a reasonable doubt that the person “(1) was convicted, 
found delinquent, or found not guilty by reason of mental 
disease or defect of a sexually violent offense; (2) is within 
90 days of release from a sentence, commitment, or secured 
correctional facility arising from a sexually violent offense; 
(3) has a mental disorder; and (4) is dangerous because that 
mental disorder creates a substantial probability that he or she 
will 
engage 
in 
acts 
of 
sexual 
violence.” 
 
Wis. 
Stat. 
§§ 980.02(2) and 980.05(3)(a); Post, 197 Wis. 2d at 297-98.   
7 A more detailed account of the witnesses’ testimony can be 
found in the court of appeals decision.  State v. Kienitz, 221 
Wis. 2d 275, 284-89, 585 N.W.2d 609 (Ct. App. 1998). 
No. 97-1460 
 
6 
substantial probability that he will commit sexually violent 
acts in the future.  Dr. Irwin based his conclusion, utilizing 
his own methodology, on several risk factors identified in 
various studies which indicated that Kienitz would commit 
sexually violent acts in the future.  Using the violence risk 
assessment guide (VRAG) which predicts recidivism for sex crimes 
as well as non-sex crimes, Dr. Irwin concluded that Kienitz was 
in the range of individuals who had a recidivism rate of 44% 
within seven years, and a 58% probability within 10 years.   
¶12 The State’s second expert witness, Dr. Sindberg, 
testified that based on his review of Kienitz’s records, there 
was a substantial probability that Kienitz would engage in 
future acts of sexual violence because his behavior was 
associated with sixteen risk factors used to predict future 
dangerousness.  In forming this opinion, Dr. Sindberg considered 
factors predictive of future sexually violent acts, and the 
effectiveness of treatment which might counteract the risk 
factors.    
¶13 The third expert witness, Dr. Caldwell, was called by 
the defense.  Dr. Caldwell explained that he used actuarial 
methods, which had established accuracy rates, instead of 
analyzing risk factors to determine the likelihood of reoffense. 
 Dr. Caldwell testified that of the five actuarial methods he 
used, the VRAG was the most reliable.  Under the VRAG, Dr. 
No. 97-1460 
 
7 
Caldwell placed Kienitz’s probability of reoffense to be in the 
range of 48% within 10 years.8  
¶14 Several lay witnesses also testified at Kienitz’s 
trial.  Sandra Reno, Kienitz’s probation agent during his term 
in 1988, discussed Kienitz’s most recent experience in the 
community.  Reno testified that during his probation, Kienitz 
was to have no contact with children, yet he obtained but did 
not report a job in a bicycle shop where he would be likely to 
have contact with children.  According to Reno, he went on 
bicycle trips with two children and their parents who he had met 
through the unreported employment.  Reno further testified that 
he had repeated contact with at least one child through an offer 
to sell his computer; he had photos, names, and phone numbers of 
children in his possession; and he was carrying ropes and a 
knife in his backpack.  
¶15 Sandy Collins, a nurse at Mendota, testified that 
while at Mendota, Kienitz was uncooperative towards staff and 
other patients.  She further stated that in 1994, Kienitz 
received in the mail, materials containing pornographic pictures 
of children, as well as a magazine containing pictures of young 
                     
8 As noted by the circuit court, both Drs. Irwin and 
Caldwell 
used 
the 
VRAG; 
however, 
they 
scored 
the 
test 
differently.  The age of index is one of the factors used in 
computing the VRAG score;  Dr. Irwin used Kienitz’s age at his 
first offense, whereas Dr. Caldwell used Kienitz’s age at the 
time of his present incarceration because of recent training he 
had received.  Dr. Irwin also increased the probability of 
reoffense based on the “ASSESS List Score,” while Dr. Caldwell 
did not make any such adjustment.  These differences resulted in 
a higher probability of reoffense as computed by Dr. Irwin.  
No. 97-1460 
 
8 
children.  According to Collins, as recently as 1995, Kienitz 
tried to mail computer diskettes to children, but did not do so 
when questioned by Mendota staff members.   
¶16 Based on the evidence before it, the circuit court 
found that the State had met its burden to prove all of the 
allegations in the petition for commitment beyond a reasonable 
doubt.  The court stated that Dr. Caldwell’s testimony, standing 
alone, would not support a finding of a substantial probability 
of future acts of sexual violence.  However, in the court’s 
view, Dr. Caldwell’s testimony coupled with Reno’s testimony of 
her supervision of Kienitz in 1988 strengthened the likelihood 
that Kienitz would engage in acts of future violence:   
At that time it had been 25 years since his first 
conviction for a sex offense.  He had been imprisoned 
from 1966 until 1973, and again from 1980 to 1988.  If 
incarceration was to have an effect on his behavior, 
it should have occurred by then.  He had been on 
probation twice previously and had been revoked both 
times.  Again, if supervision in the community was to 
improve Mr. Kienitz’s behavior, the improvement should 
have taken place by that time.  While on parole in 
1988, Mr. Kienitz was 50 years old.  He was on 
intensive supervision, with rules designed to help him 
avoid contact with children and the opportunity to re-
offend.  He broke these rules in many, serious 
respects. 
 
The 
violations 
were 
very 
deliberate. . . . The testimony of Sandra Reno left no 
doubt that in 1988 Mr. Kienitz was extensively engaged 
in efforts to meet and spend time with children with 
the intent of engaging in future sexual behavior with 
them. . . .  
  It is now 8 years later.  Mr. Kienitz has engaged in 
no significant treatment for his pedophilia since 
being reincarcerated in 1988.  He does not communicate 
any plan to deal with his disease.  If released, he 
will not be under supervision.  Experience over the 
last 33 years of his life, especially the most recent 
No. 97-1460 
 
9 
episode of being in the community coupled with the 
test results obtained by Dr. Caldwell, persuade me 
beyond a reasonable doubt that there is a substantial 
probability that Mr. Kienitz will engage in future 
acts of sexual violence if released.  
The court committed Kienitz to institutional care in a secure 
mental health facility.  Subsequently, Kienitz filed post-
verdict motions which the circuit court denied. 
¶17 The court of appeals affirmed the circuit court’s 
order.  Rejecting Kienitz’s arguments, the court of appeals 
concluded that there was sufficient evidence from which a 
reasonable trier of fact could find beyond a reasonable doubt 
that there was a substantial probability that Kienitz would 
commit future acts of sexual violence.  Kienitz, 221 Wis. 2d at 
307.  The court dismissed Kienitz’s constitutional challenge.  
Id. at 309-10.   
II. 
¶18 We now turn to Kienitz’s challenge to the sufficiency 
of the evidence.  Kienitz argues that the evidence relied upon 
by the circuit court is insufficient to establish a substantial 
probability of reoffense.  Substantial probability to reoffend 
means “much more likely than not” that a person will engage in 
future acts of sexual violence.  Curiel, 97-1337, op. at 31.   
¶19 According 
to 
Kienitz, 
the 
circuit 
court’s 
determination is based on double counting of factors already 
taken into account by Dr. Caldwell and erroneous factual 
findings. 
¶20 We 
utilize 
the 
criminal 
standard 
of 
review 
to 
determine whether there is sufficient evidence to prove a person 
No. 97-1460 
 
10
was a sexually violent person subject to commitment.  Id. at 27-
28.  We may not reverse the commitment based on insufficient 
evidence: 
unless the evidence, viewed most favorably to the 
state and the [commitment], is so insufficient in 
probative value and force that it can be said as a 
matter 
of 
law 
that 
no 
trier 
of 
fact, 
acting 
reasonably, could have found [the defendant to be a 
sexually violent person] beyond a reasonable doubt. 
Id. at 26 (quoting State v. Poellinger, 153 Wis. 2d 493, 501, 
451 N.W.2d 752 (1990)).   
If any possibility exists that the trier of fact could 
have 
drawn 
the 
appropriate 
inferences 
from 
the 
evidence adduced at trial to find [that the defendant 
is a sexually violent person], an appellate court may 
not overturn a verdict even if it believes the trier 
of fact should not have found [the defendant to be a 
sexually violent person] based on the evidence before 
it. 
Poellinger, 153 Wis. 2d at 507.  The trier of fact determines 
issues 
of 
credibility, 
weighs 
the 
evidence 
and 
resolves 
conflicts in testimony.  State v. Gomez, 179 Wis. 2d 400, 404, 
507 N.W.2d 378 (Ct. App. 1993).   
 
¶21 Kienitz 
first 
argues 
that 
the 
circuit 
court’s 
assessment of the evidence was fatally marred because it double 
counted evidence.  According to Kienitz, the court relied upon 
the VRAG score which figured in his prior record and failures on 
supervision, and then it enhanced Kienitz’s probability to 
reoffend based on these same facts.  Kienitz seems to suggest 
that the court could not consider any evidence factored into his 
expert’s measure of dangerousness. 
No. 97-1460 
 
11
 
¶22 The court of appeals correctly noted that “[t]he 
[circuit] court was not obligated to accept the weight Dr. 
Caldwell assigned the various factors in his scoring of the 
VRAG, nor was it obligated to choose either Dr. Caldwell’s or 
Dr. Irwin’s VRAG score and rely solely on that score as a 
measure of probability.”  Kienitz, 221 Wis. 2d at 308.  The 
trier of fact has the ability to accept so much of the testimony 
of a medical expert that it finds credible, State v. Owen, 202 
Wis. 2d 620, 634, 551 N.W.2d 50 (Ct. App. 1996), and it then 
weighs the evidence and resolves any conflicts in testimony.  
Gomez, 179 Wis. 2d at 404. 
 
¶23 We find that the evidence was more than sufficient to 
establish beyond a reasonable doubt that it was “much more 
likely than not” that Kienitz would engage in future acts of 
sexual violence.  Curiel, 97-1337, op. at 31.  It is evident 
from the court’s decision that it placed great weight on 
Kienitz’s 25 year criminal history in which he displayed 
insignificant improvement despite incarceration and treatment 
efforts, and supervision in the community; his deliberate 
violations of his rules of supervision, and preparation to 
reoffend in 1988; his denial of the need for treatment9; and his 
                     
9 The court included the following in its findings of fact: 
 In 1990, Kienitz viewed himself as “cured” of pedophilia.  In 
1993, he did not view himself as having a problem with 
pedophilia.  In 1994, Kienitz stated he is no longer a pedophile 
and declined treatment.  He also refused to participate in any 
planning for community living and stated that he preferred to 
remain institutionalized until his mandatory release date rather 
than have the restrictions of parole.  As recently as 1996, 
Kienitz denied the need for treatment for his pedophilia. 
No. 97-1460 
 
12
recent involvement with materials relating to or for children 
while at Mendota.  The weight the court attached to this 
evidence is supported by portions of the testimony of all three 
experts.  The circuit court was entitled to rely on this 
evidence in determining that it was much more likely than not 
that Kienitz would reoffend.   
¶24 We also conclude, as did the court of appeals, that 
the circuit court’s erroneous factual findings do not affect our 
conclusion 
on 
the 
sufficiency of 
the 
evidence.  
It is 
uncontested that the circuit court erred in finding that Kienitz 
was convicted of first-degree sexual assault on November 15, 
1977, and again on February 10, 1978.  Both dates involved the 
same charge with the plea entered on the first date, and the 
sentencing on the second date.   
¶25 Kienitz argues, 
however, 
that the 
circuit 
court 
“unfairly inflated his prior record” and the error was critical 
to the circuit court’s assessment of dangerousness.  We note 
that the error contained in the court’s findings of fact and 
conclusions of law did not carry over into its decision.  The 
court correctly stated that as of 1988, it had been 25 years 
since Kienitz’s first conviction, he had been imprisoned from 
1966 until 1973, and again from 1980 to 1988; he had been on 
probation twice previously and had been revoked both times; and 
while on parole in 1988, Kienitz very deliberately violated his 
rules of supervision and “was extensively engaged in efforts to 
meet and spend time with children with the intent of engaging in 
future sexual behavior with them.” 
No. 97-1460 
 
13
¶26 It is clear from the circuit court’s decision that it 
did not rely on a specific number of offenses; rather, it 
considered significant, among other things, the substantial 
number of prior sexual offenses, as well as Kienitz’s history, 
since his original conviction, of reoffending or preparing to 
reoffend while under supervision.10  We conclude that the State’s 
evidence was not so lacking in probative value that no trier of 
fact, acting reasonably, could have drawn the appropriate 
inferences from the evidence to find beyond a reasonable doubt 
that Kienitz is a sexually violent person under Wis. Stat. ch. 
980.    
III. 
¶27 Underlying Kienitz’s argument on the sufficiency of 
the evidence, is his perception of the role of expert testimony 
in such a determination.  Kienitz insists that a determination 
of dangerousness under Wis. Stat. ch. 980 must be based on 
expert testimony.  Because the only expert found reliable by the 
circuit 
court, 
Dr. 
Caldwell, 
testified 
there 
was 
not 
a 
substantial probability that Kienitz would reoffend, Kienitz 
argues that the evidence was insufficient to commit him.   
                     
10 The United State Supreme Court has commented in Jones v. 
United States, 463 U.S. 354, 364 (1983) that: 
The fact that a person has been found, beyond a 
reasonable doubt, to have committed a criminal act 
certainly 
indicates 
dangerousness. 
 
Indeed, 
this 
concrete evidence generally may be at least as 
persuasive as any predictions about dangerousness that 
might be made in a civil-commitment proceeding.   
No. 97-1460 
 
14
¶28 We first address Kienitz’s mistaken premise that the 
circuit court found only Dr. Caldwell’s testimony to be reliable 
in predicting dangerousness.  In its decision, the circuit court 
stated that Dr. Caldwell’s testimony was “more persuasive” than 
Drs. Irwin and Sindberg; however, the court nevertheless found 
“the testimony of the experts in this case. . . useful and 
informative and [the court] relied heavily upon it.”11  The trier 
of fact is not bound by the opinion of an expert; rather, it can 
accept or reject the expert’s opinion.  State v. Sarinske, 91 
Wis. 2d 14, 48, 280 N.W.2d 725 (1979); Pautz v. State, 64 Wis. 
2d 469, 476, 219 N.W.2d 327 (1974); State v. Owen, 202 Wis. 2d 
620, 634, 551 N.W.2d 50 (Ct. App. 1996)(trier of fact may accept 
certain portions of an expert’s testimony while disregarding 
other portions).  We agree with the court of appeals that even 
though the circuit court “found Dr. Caldwell’s methodology more 
reliable than [that of the other two experts], it does not 
follow that the court could not, or did not, credit portions of 
                     
11 At the post-verdict motion, the circuit court stated: 
I chose not to rely particularly heavily on the 
State’s two psychological experts and relied frankly 
more heavily on [Kienitz’s] own expert and the 
testimony of Ms. Reno.  All of the testimony supports 
the conclusion that I reached. 
 
  The court is not bound by the conclusion of any 
expert.  The court can consider the opinions of 
experts insofar as they assist in reaching a decision, 
and I did consider the opinions of all of the 
witnesses in reaching my conclusion. . . .  [Emphasis 
added.] 
 
No. 97-1460 
 
15
their testimony in making its determination.”  Kienitz, 221 Wis. 
2d at 303-04.   
¶29 Kienitz also makes the argument that a determination 
of dangerousness under Wis. Stat. ch. 980 must be based on 
expert 
testimony. 
 
In 
essence, 
Kienitz 
insists 
that 
a 
determination 
of 
dangerousness 
cannot 
be 
made 
without 
statistical evidence on the probability of reoffense provided by 
an expert, irrespective of other non-expert testimony and 
empirical evidence.12  
¶30 Neither this court, nor the United States Supreme 
Court have squarely addressed whether expert testimony is 
required 
for 
a 
determination 
on 
the 
question 
of 
future 
dangerousness.  In a decision addressing the standard of proof 
in civil commitments, the Supreme Court commented “[w]hether the 
individual is mentally ill and dangerous to either himself or 
others and is in need of confined therapy turns on the meaning 
of the facts which must be interpreted by expert psychiatrists 
and psychologists.”  Addington v. Texas, 441 U.S. 418, 429 
(1979).  This was not, however, the holding in the case.  Id. at 
432-33.  The Supreme Court has also held that expert testimony 
about a defendant’s future dangerousness, while not required at 
                     
12 As the court of appeals observed, Wis. Stat. ch. 980 does 
not require experts testifying in ch. 980 proceedings to adhere 
to one particular behavioral science methodology to predict 
future sexual violence, such as Dr. Caldwell’s actuarial 
methods.  Kienitz, 221 Wis. 2d at 307.  We agree that such a 
requirement would dissolve the important distinction between the 
legal and behavioral science standards discussed in Post, 197 
Wis. 2d at 310-11.   
No. 97-1460 
 
16
the penalty phase of a capital murder trial, is admissible.  
Barefoot v. Estelle, 463 U.S. 880, 898-901 (1983), superceded on 
other grounds by statute, 28 U.S.C.A. § 2253(c)(2)(West Supp. 
1999); Smith v. Estelle, 451 U.S. 454, 472-73 (1981).   
¶31 Because there was expert testimony on the issue of 
future acts of sexual violence in this case, we need not decide 
the broader question of whether expert testimony is required as 
a matter of law.  See Weiss v. United Fire & Cas. Co., 197 Wis. 
2d 365, 379, 541 N.W.2d 753 (1995); Netzel v. State Sand & 
Gravel Co., 51 Wis. 2d 1, 6, 186 N.W.2d 258 (1971); and Cramer 
v. Theda Clark Mem. Hosp., 45 Wis. 2d 147, 150, 172 N.W.2d 427 
(1969). 
¶32 The credibility of witnesses and the weight given to 
their testimony are matters left to the trier of fact.  State v. 
Friedrich, 135 Wis. 2d 1, 16, 398 N.W.2d 763 (1987). It is the 
trier of fact’s task to sift and winnow the credibility of the 
witnesses.  State v. Toy, 125 Wis. 2d 216, 222, 371 N.W.2d 386 
(Ct. App. 1985). 
¶33 This includes testimony by experts.  “The credibility 
of an expert witness and the weight the trier of fact is going 
to give to his [or her] testimony, as contrasted to other 
witnesses, is always an issue that is properly before the trier 
of fact.”  Curiel, 97-1337, op. at 30-31.  This court has never 
bound the trier of fact to the opinion of an expert; rather, it 
can accept or reject it.  Sarinske, 91 Wis. 2d at 48; Pautz, 64 
Wis. 2d at 476; Owen, 202 Wis. 2d at 634 (trier of fact may 
No. 97-1460 
 
17
accept 
certain 
portions 
of 
an 
expert’s 
testimony 
while 
disregarding other portions).   
¶34 In this case, the testimony of Drs. Irwin, Sindberg, 
and Caldwell was admissible as expert testimony.  See State v. 
Zanelli, 212 Wis. 2d 358, 379, 569 N.W.2d 301 (Ct. App. 1997).  
All three experts opined about the nature of Kienitz’s disorder; 
the risk factors that are, or are not predictive of recidivism; 
and whether those factors were, or were not applicable to 
Kienitz.  Empirical evidence was provided by Kienitz’s probation 
agent and a nurse from Mendota.   
¶35 Based on Wisconsin’s standards, we conclude that the 
circuit court, as the trier of fact, “was free to weigh the 
expert’s testimony when it conflicted and decide which was more 
reliable; to accept or reject the testimony of any expert, 
including accepting only parts of an expert’s testimony; and to 
consider all of the non-expert testimony in deciding whether 
[there] was [a substantial probability] that Kienitz would 
commit future acts of violence.”  Kienitz, 221 Wis. 2d at 307.   
IV. 
¶36 Kienitz’s final argument is that if the evidence is 
sufficient 
to 
support 
a 
commitment, 
then 
the 
order 
for 
commitment violates his right to due process under the United 
States and Wisconsin constitutions.  Kienitz argues that Dr. 
Caldwell, the only expert found reliable by the circuit court, 
determined that Kienitz’s risk of reoffending was 48% or not 
more than “kind of a coin toss situation.”  Kienitz argues that 
a less than 50% chance of reoffending does not comport with the 
No. 97-1460 
 
18
Wis. Stat. ch. 980 dangerousness standard.  We reject Kienitz’s 
due process argument because it is based on two premises which 
we have previously dismissed.   
¶37 In part II of this decision, we addressed and denied 
Kienitz’s argument that the court’s assessment of the evidence 
was flawed by its misunderstanding of his prior record and its 
double counting of factors already taken into account by Dr. 
Caldwell’s actuarial method.  We held that the State’s evidence 
was not so lacking in probative value that no trier of fact, 
acting reasonably, could have drawn the appropriate inferences 
from the evidence to find beyond a reasonable doubt that Kienitz 
is a sexually violent person under Wis. Stat. ch. 980. 
¶38 We also discussed, in part III of the opinion, 
Kienitz’s argument that the circuit court found only Dr. 
Caldwell’s testimony to be reliable in predicting dangerousness. 
 We determined that the circuit court was clear, in its 
memorandum decision and its statements at the post-verdict 
motion, that it found the testimony of all of the experts in 
this case to be useful and informative.  The circuit court 
further explained that it considered the opinions of all of the 
witnesses in reaching its conclusion.  The court, as the trier 
of fact, is not bound by the testimony of one expert.  Sarinske, 
91 Wis. 2d at 48.  Rather, it is free to accept of reject the 
testimony of any expert, and to consider all of the non-expert 
testimony 
in 
deciding 
whether 
there 
was 
a 
substantial 
probability that Kienitz would commit future acts of sexual 
violence.   
No. 97-1460 
 
19
¶39 In Curiel, we held that “substantially probable,” 
which means “much more likely than not,” provides proper 
standards of adjudication, and is not so obscure that people of 
common intelligence must necessarily guess at its meaning and 
differ as to its applicability.  Curiel, 97-1337, op. at 24.   
¶40 In summary, we hold in this case that the evidence was 
more than sufficient to establish beyond a reasonable doubt that 
it was much more likely than not that Kienitz would engage in 
future acts of sexual violence.  As applied here, we also 
conclude that the standard for dangerousness under Wis. Stat. 
ch. 980 does not violate Kienitz’s due process rights as 
guaranteed by the United States and Wisconsin Constitutions.   
By the Court.—The decision of the court of appeals is 
affirmed. 
¶41 DAVID T PROSSER, JR., J.   did not participate. 
No. 97-1640 
 
1