Up next, a chance
encounter results in a vicious m*rder.
The first people to
arrive discovered a very brutal scene.
There was a lot of blood.
And a lot of suspects.
We're talking, in years of work,
we eliminated over 400 people.
Investigators carry on
despite setback after setback.
While this case may have
grown cold, it was never closed.
Then forensic science,
from an unrelated crime,
helps expose a k*ller.
For whatever reason,
this case just draws you in,
and you want to be a part of it.
Wisconsin is one of
the Great Lakes states
notorious for brutal winters.
But for reasons no one could
later explain,
on a December night in 1984,
a young woman decided to brave
the bitter weather
and walk home.
It was snowing and it was cold.
She had to walk a number
of miles to her home.
A few hours later, a
man went out to get his newspaper
and came upon a shocking sight.
The body was discovered
along a gravel driveway.
It was a female.
She was laying on her back.
She was naked
from the breast down.
Her head was bloodied.
It was evident that she had
been bludgeoned
on the right side of her head.
Even veteran
detectives were stunned
by this level of v*olence.
The victim had been struck
with such force
that cast-off blood spatter,
which flies off a w*apon
during repeated strikes,
had traveled all the way up
into the surrounding trees.
She had been
violently strangled, r*ped,
and beaten in the head a number
of times by this metal object.
The rage and how violent
the scene was really...
was disturbing.
The m*rder w*apon
was not at the scene.
Blood evidence made it clear
the victim had been k*lled
where she was found.
Since she wasn't frozen,
and temperatures were frigid,
police knew she hadn't
been there long.
She was identified
as 18-year-old Traci Hammerberg.
Traci was a friendly girl.
She was friends with just
all the groups
that one might encounter,
you know,
in your typical high school.
She did have some rough patches
at home.
She had some things she was
dealing with, like most,
you know, like typical
high schoolers at the time,
and like today.
On the morning Traci
was k*lled, there was fresh snowfall,
a potential break
for investigators.
There were some tire tracks
that had been left in the snow.
There was also a pack
of Marlboro red cigarettes
that had been found
in the snow also.
Traci's m*rder took
place in a very rural area,
aside a long driveway,
well away from any houses.
But, in another possible break,
there were two
potential witnesses.
There was a hunter...
it was deer hunting season...
and he had been out
about 5:45 in the morning.
And he heard a car accelerating
at a high rate of speed.
He saw the car come out of
the driveway of the residence,
without any headlights on.
Another hunter says
that he observes a dark sedan
traveling at
a high rate of speed.
But this was all the detail
these two witnesses
could provide.
The task now was for detectives
to backtrack
Traci's final hours.
Her night began
innocently enough.
She babysat for a friend,
and then she had some friends
pick her up to take her
to a party at this house.
Nothing unusual
for a Friday night.
They played
a drinking game called quarters,
where you bounce
a quarter into a cup
and then decide
who drinks the cup of beer.
They did that for some time.
Some partygoers said
Traci left about 12:30,
but that seemed to be
all they agreed about.
Everyone we talked to had
a different way
that Traci had left
the residence.
And there were a lot of holes
in what they were telling us.
It created some suspicion
on what had occurred
at that residence
and what time Traci
had actually left.
For some inexplicable reason,
they would not settle
on one story.
Which led to a lot of
questions about a cover-up,
and what, or who,
these partygoers were hiding.
Traci Hammerberg's
autopsy confirmed
what detectives
at the scene surmised.
She was sexually assaulted.
She was strangled.
She was bludgeoned with
what they described
as a metallic object.
They believed that the
w*apon was a metallic w*apon,
similar in nature
to a tire iron.
A possible clue was
a class ring on her left hand
with the initials
"GDW" engraved on the inside.
This was tracked back to Traci's
boyfriend, Glenn Whagner.
But he was out-of-state
the night of the m*rder
and was eliminated.
Another clue... skin cells
under Traci's fingernails,
a clear sign
she had fought for her life.
A r*pe kit was performed.
But in 1984, the resulting
genetic evidence
was of limited value.
At the time
the crime was committed,
DNA was not around yet.
We weren't using that
in the laboratories.
The most common thing to do
was A.B.O. blood-group typing,
so that was initially what was
done early on in the case.
"A.B.O. blood typing" refers
to the major blood types
found across all populations.
Traci's k*ller had type O blood,
not exactly rare,
but a valuable tool to connect,
or eliminate,
potential suspects.
In this particular case,
the A.B.O. blood-group type
was the limit
of what we could do,
and then make comparisons
to particular individuals
that law enforcement
would submit.
Before Traci left the beer party
the night of the m*rder,
a friend named David Drake
offered her a ride home.
By all accounts,
she turned down the offer,
despite the bad weather.
Traci not taking a ride
on a December night
in Wisconsin is unusual.
While
questioning other partygoers,
detectives learned that,
earlier that night, David Drake
arrived late to the party.
David says he's later than usual
because he had a flat tire.
Later, he's questioned
about that flat tire,
he's questioned
about the tire iron
that he used to change
that flat tire,
and he cannot explain that, why
he doesn't have the tire iron.
He says he lost it
while he was changing the tire.
What's the odds of
somebody getting a flat tire
and losing the tire iron
on a night
that a girl at his house
gets m*rder*d,
and we believe the potential
m*rder w*apon is a tire iron?
But his blood type
was not type O,
and that eliminated him
as a suspect.
Meanwhile, Traci's m*rder
was big news in rural Wisconsin.
And one tip, about a man
named Dale Schultz,
was of particular interest
to detectives.
Interviews with people
who surrounded Dale,
he was violent.
He would lose his temper.
He abused women.
It was determined that
Dale knew Traci at the time,
had potentially dated Traci,
had prior incidents
with other girlfriends
where he became very violent,
actually threatened
one of his former girlfriends
with a tire iron.
So he became a very
good suspect.
He became an even better suspect
when police heard a strange
story about Dale Schultz
from around the night
of Traci's m*rder.
He was seen with blood
on his jacket.
Dale informed the investigator
that he was involved
in a bar fight,
and that's the reason that
the blood was on his jacket.
For detectives, this seemed
like more than a coincidence.
And Schultz's alibi for
the period of the m*rder
wasn't exactly airtight.
He was at a bar.
Alcohol was involved.
The memories of potential alibi
witnesses were sketchy.
Even more damning
for investigators
was the blood test.
Dale Schultz was type O.
Everything pointed
in his direction,
but there was
no conclusive proof.
No arrest was possible,
at least for now.
There were just no answers
to any of the questions
that were there.
The v*olence of that encounter
with Traci
was something
that no one took lightly.
I think it caused a realistic
fear of,
"What is happening
in our community?"
And that fear lingered
for years,
until the arrest
of a serial k*ller
thousands of miles away
created a path to the man
who m*rder*d Traci.
Weeks and then months
went by with no arrests
in Traci Hammerberg's m*rder.
The community was on edge.
There was a fear of,
"How did this happen?"
There were just no answers
to any of the questions
that were there.
It struck a nerve in that area.
There were a lot of people,
a lot of young people,
that, you know, used to take
rides or would go to parties
without asking too
many questions.
Then, all of a sudden,
things changed.
Early in the
investigation into Traci's m*rder,
detectives' main tool
was the k*ller's blood type.
As the years passed
and DNA technology evolved,
analysts generated
the k*ller's DNA profile.
The best that
we could do at the time
was just analyze
a bloodstain card
from an individual
or their buccal swab,
and compare that profile
to the evidence profile
and determine whether it was
a match or an elimination.
With this early DNA technology,
detectives attempted
to test anyone
with even
a remote connection to Traci.
The testing,
what came to be known
as a "DNA dragnet,"
eliminated Dale Schultz,
the only solid suspect
in the case,
as well as more than 400 men
who were also tested.
So, despite the finding of DNA
and nearly unprecedented
testing of potential suspects,
Traci's case was back
to square one.
It really got to the point
where we were making some phone calls
to the state crime lab, asking,
"Are we sure about this?
Is there something
that could be wrong?"
DNA databases worldwide
were growing by the day.
If Traci's k*ller committed
any other violent offense,
which, given the nature
of the crime, seemed likely,
his DNA should end up in CODIS,
the U.S. criminal DNA database.
This profile in
particular was entered into CODIS
in July of 2000.
At that time, the database
wasn't necessarily that large.
It did not hit at the time,
and over the course of decades,
it still hadn't hit in CODIS.
Nearly 20 years passed.
No new suspects emerged.
Neil McGrath was assigned
to the case in 2005.
I read through
the entire case file,
reviewed photos and video
from the evidence.
What really made an impression
on me
was how violent the crime was.
I felt a real responsibility
to find the individual
that had done this to Traci
and get him off the street.
It was never a cold case.
It was a case that was always
being worked on
in some capacity.
And finally, that
diligence appeared to pay off.
We heard about a different way
of conducting DNA.
We heard about forensic
genetic genealogy.
In 2018, the notorious
Golden State k*ller
was finally identified
thanks to a new breakthrough
in DNA technology.
When the
Golden State k*ller had happened
and they heard about this use
of genetic genealogy,
they immediately went to,
"Well, hey,
can we use genetic genealogy
in this case?"
This had the potential
to identify Traci's k*ller.
But there was one problem.
And it was a big one.
In 2018, investigators
thought we had used
our entire sample of DNA.
Genetic genealogy
required a "fresh" DNA sample.
You need quite
a bit of DNA at the time
in order to develop
the type of profile
that is utilized
for genetic genealogy,
and we didn't think there was
anything left to go back to.
In Traci Hammerberg's case,
the original DNA sample
from her m*rder
was copied countless times,
using a process called PCR
and ultimately entered
into the CODIS database.
But the part of a DNA sample
needed for genetic genealogy
is different.
For genetic genealogy, the type
of DNA testing that's utilized
is single-nucleotide
polymorphisms,
or SNPs is the acronym for it.
To do that type of testing,
analysts needed something
from the original DNA sample.
But that might not be possible.
Because of the amount
of testing that was done,
the majority of
the initial sample was used up.
When we determined that
genetic genealogy
would be the course
we would take with Traci
and her case,
the problem we had was
we did not think we had any DNA
left from the suspect.
In an attempt to save the case,
Detective Scott Heller went back
to the original evidence file,
which had been sitting
in storage
for nearly three decades.
Scott Heller went through
every piece of evidence
that had been collected
over the years,
made contact with people
at the crime lab
to discuss what potentially
could have DNA on it,
what might not.
We found one envelope,
the one that was
dated correctly,
the one with
the right identifiers,
and I think, at first,
we couldn't believe
what we were seeing.
We had what we believed was
going to give us the best chance
to develop that profile
to find Traci's k*ller.
It was exciting.
It was...
We were beside ourselves.
This was a DNA extract
remaining from the original DNA swabs.
To the relief of investigators,
a SNP DNA profile was generated.
The question now was
whether genetic genealogy
could expose Traci's k*ller.
The key would be accessing the
vast amounts of genetic material
stored in both public
and private DNA databases.
There's a database of people,
particularly through companies
such as 23andMe and ancestry.com
where people are submitting
their DNA
for their own personal use.
And then those databases can be
searched for the purposes
of law-enforcement
investigations.
The suspect's DNA is
compared to the genetic profiles
of millions of people.
Some of these people,
from all over the world,
may share small amounts of DNA
with the suspect.
Slowly, this technology creates
an extended genetic family tree.
The information that I was given
was there was some matches
to maybe a second or
third cousin in the family tree.
And it was just a matter of then
building out the tree
to find what family
this individual was a part of.
I always looked at it
like walking into a stadium.
You know your suspect's
in that stadium,
and you can narrow it down
through the SNP
from the section and to the row,
and then ultimately
to the seat number
where your suspect's gonna be.
As the list of possible suspects
was narrowed down,
analysts looked for males
who would have been
living in Wisconsin,
way back in 1984.
We found a second
marriage in a family tree,
and from that,
produced two brothers
that had lived
in Port Washington.
As we looked at
their background,
we found that one brother
was in a lot of trouble,
had been to prison.
His name was Philip Cross.
He was 21 years old at the time
of Traci's m*rder.
Traci knew Philip Cross
from riding the bus
when they were younger,
in school.
Investigators also
discovered that Philip Cross
smoked Marlboro red cigarettes,
just like the pack of cigarettes
found at the crime scene.
And he was suspected
of previous incidents
with eerie similarities
to Traci's m*rder.
He met a girl at a bar
and got a ride home from her.
As she was giving him a ride
home, he took off his belt,
put it around her neck,
and started choking her.
She was able to slam
on the horn and break free,
while Philip went running away.
Cross was never
charged in this incident,
so his DNA didn't
get entered into CODIS.
Detectives tracked him down
and found him
in coroner's records.
He d*ed of a drug overdose
DNA saved from his autopsy
left no doubt he was the k*ller.
The news was
bittersweet because we wanted
that suspect to face justice.
He was able to live his life.
Traci wasn't given
that same opportunity.
A background check showed
Philip Cross worked at a factory
near Traci's location
the night of the m*rder.
His shift would've ended about
the time she was walking home.
Investigators believe
he offered her a ride,
and the evidence indicates
she entered his car.
They drove to the isolated
spot along the driveway.
It appears Cross made a sexual
advance, which Traci rebuffed.
The evidence indicates
he choked her,
almost to death,
sexually assaulted her,
then he b*at her to death
with what they suspect
was a tire iron.
But unknown to him,
he left conclusive proof behind.
It just took nearly 35 years
for DNA technology
to finally reveal it.
It's touched a lot of people.
I was a third-generation
detective that had helped out
with this investigation.
We were trying to use
every investigative technique
that we could
to locate this k*ller.
And fortunately, science had
advanced to a point
that allowed us to do that.
We're in this
because we want to help others,
we want to bring closure
to people,
we want to help solve your case.
A case like this that's been
around for such a long time,
it becomes part of you in a way.
You don't want to give it up.
You want to be the analyst,
the final analyst,
that writes that report
that solves that case.