Triple homicide case relies on DNA evidence
Photo 
James C. Koepp during his Rock County Court House appearance at a preliminary hearing in the triple homicide.
JANESVILLE — When the Janesville triple homicide trial begins in January, DNA will play a key role.
Prosecutors claim the victims’ DNA was linked to bloodstains on the jeans and shirt that James Koepp wore on the night of the homicides.
Defense attorneys claim DNA from an unknown assailant was found on a ligature and knives at the murder scene.
Koepp, 50, faces three charges of first-degree intentional homicide in the January 2007 slayings of Danyetta Lentz and her teenage children, Nicole and Scott.
A pathologist said strangulation by ligature and stab wounds contributed to their deaths.
Jurors will have to decide whether DNA shows that Koepp or someone else is the killer.
Attorneys on both sides appeared in Rock County Court on Tuesday to argue whether an unknown assailant defense would be allowed at trial. Koepp didn’t attend the hearing.
District Attorney David O’Leary filed a motion asking the judge to keep the unknown assailant defense out.
Koepp’s attorney, assistant public defender Walter Isaacson, said Koepp has a right to undermine the state’s DNA evidence.
He said the state crime lab found DNA from an unknown male on a ligature, knife handles and other items at the crime scene.
Judge Alan Bates sided with the defense attorney, saying the unknown assailant defense could be used at trial.
Meanwhile, attorneys argued over the testimony of a DNA expert that the defense wants to call at trial.
State statutes require attorneys on both sides to exchange evidence or testimony they intend to present at trial. Attorneys then have an opportunity to review each other’s cases to prepare.
O’Leary said a defense expert’s report offers no opinion challenging the state’s DNA evidence. He said he hasn’t been told what the defense expert will say at trial.
“It’s not fair to the state,” O’Leary said. “It’s trial by ambush.”
Isaacson denied the prosecutor’s accusations, saying the expert will testify about DNA transfer and other elements of her expertise.
The judge decided the expert could only testify about information in her report. He ruled the expert can’t provide opinions not shared with prosecutors.
If convicted, Koepp faces three life sentences.
A hearing is scheduled for Tuesday, Jan. 19.
Koepp’s two-week trial is scheduled to begin Jan. 25.
Jan 14, 2010 at 5:16 p.m.
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First of all he tried to rape my sister! For your info...why don't you all just come to the trial and hear all the evidence against this man than you'll understand the case alot better than just reading articles.I guess it would be totally different if it was your family being tortured to death the way mine was.I trust the teams that worked on this case to the fullest.I believe his attorney is trying to bark up the wrong tree.Maybe he did have help..maybe his wife...who knows...we'll find out at trial!!!
Jan 13, 2010 at 6:55 a.m.
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Hey Mickie, that is called tunnel vision, they
"think" they have the right guy, I sympathize for the family, the DNA they have only proves he had sex with the woman, it does not prove he committed the act, so let them hold this guy on some BS unrelated charge until we can gather evidence against him. The idea behing out CJ system is "innocent until proven guilty" The D.A. is not even entertaining the idea that maybe someone else did this. Anyone else caught the way this guy was would have been out on bail already. Their trying this guy on circumstantial evidence and his past,their hoping that they will find something else.
Dec 24, 2009 at 11:55 a.m.
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After this trial maybe they'll go get this guy/gal. It seems this is his way "off" so they wouldn't share this till he gets off for murder then they'll go after this other person that was there too?
Didn't they take samples from EVERYBODY that may have been in there there they knew of?
Dec 24, 2009 at 9:50 a.m.
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What is bothersome is that if there is someone else`s DNA- then that would have been known very early on.. So why has there not been any other arrests? Why has there not been enough proof that anyone is even looking for another party. This is beyond disturbing that we may have a "killer" still running around our streets..
Dec 24, 2009 at 8:31 a.m.
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I don't recall him ever saying he found them.
OJ had blood all over him too.
Dec 23, 2009 at 10:19 p.m.
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OJ ran (well got driven) when he was under suspicion, but didn't have to explain that at all.
Dec 23, 2009 at 6:49 p.m.
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One could argue that he found the victims (hence the blodd/DNA on his clothes)and was traumatized by the discovery...
That unknown DNA bothers me...
Dec 23, 2009 at 5:57 p.m.
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So, maybe there was another person there WITH him. Is HIS DNA on the knife and thing they strangled them with? Their DNA is on his clothes. HOW does he explain that? Why did he RUN just before questioning? I think the wife will be on DA side. They are divorced now.
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