00:00:04
[Music]
00:00:06
most homeowners would prefer grass to a
00:00:08
lawn full of weeds
00:00:10
but the forensic scientists weeds can
00:00:12
tell a story
00:00:14
with the help of a plant biologist and a
00:00:16
new high-tech computer program
00:00:19
investigators solved the mystery of a
00:00:22
young girl's murder
00:00:24
[Music]
00:00:52
weekends were typically busy in the
00:00:54
mauser household
00:00:57
one saturday morning in 1995 as kathy
00:01:00
mouser was leaving for work she reminded
00:01:03
her 14 year old daughter jenna that she
00:01:06
was grounded for the weekend and wasn't
00:01:08
allowed to use the telephone either
00:01:11
jenna was having some behavioral issues
00:01:13
a lot of 14 year olds 15 year olds might
00:01:15
have those kinds of issues when they're
00:01:16
growing up lots of pressure social
00:01:18
pressures problems within the family
00:01:20
she was having such trouble that the
00:01:23
family was taking her to counseling
00:01:25
kathy returned home from work around 1pm
00:01:29
and as soon as she tried to open the
00:01:30
door
00:01:32
she knew something was wrong
00:01:34
mrs mauser found the front door lock
00:01:36
which she said was unusual because
00:01:38
usually there's there's somebody there
00:01:40
and she was expecting jenna to be there
00:01:42
so the front door would have been
00:01:43
unlocked
00:01:45
jenna wasn't home
00:01:46
and she hadn't left the note saying
00:01:48
where she went
00:01:50
they just figured she was upset and she
00:01:52
would basically just walked away you
00:01:54
know or she was just with one of her
00:01:56
friends or
00:01:58
yeah none of the neighbors saw jenna
00:02:00
leave or noticed anything suspicious
00:02:04
when jenna's stepfather and brother
00:02:05
arrived home several hours later
00:02:08
they searched the neighborhood and
00:02:10
called all her friends
00:02:12
but no one knew where jenna was
00:02:16
later that night the mousers called
00:02:18
police to report their daughter missing
00:02:21
the next morning the mousers learned
00:02:24
that the nude body of a teenaged girl
00:02:26
was discovered in a ditch about 20 miles
00:02:30
outside of town
00:02:32
the family identified
00:02:35
jenna's body
00:02:36
at the morgue
00:02:38
the reality of
00:02:40
her being murdered
00:02:41
rather than an accident or
00:02:44
it didn't hit me i didn't understand
00:02:48
really that that something like that
00:02:49
could happen
00:02:51
in my life
00:02:54
it was it was hard to deal with
00:02:56
and and to it was just such an unfair
00:02:59
act
00:03:00
and i couldn't couldn't understand it
00:03:02
for a long time
00:03:04
the coroner identified the cause of
00:03:06
death
00:03:07
as strangulation
00:03:09
there were other injuries as well
00:03:11
in addition to the ligature
00:03:13
strangulation marks she also had
00:03:15
evidence of blunt force injury to the
00:03:17
head she had received a blow to the head
00:03:20
in the left forehead area and the left
00:03:22
temple
00:03:23
there were no defensive wounds
00:03:25
and no signs of sexual assault the scalp
00:03:28
here is brown about 14 inches in length
00:03:31
well the soles of the feet were clean in
00:03:33
this case and that indicates to me that
00:03:35
she certainly was not
00:03:37
standing up at the scene where she was
00:03:40
found and she certainly did not walk
00:03:42
there
00:03:43
the only other findings were some
00:03:45
unusual marks on jenna's thigh
00:03:48
indentations that were made
00:03:51
after death
00:03:52
on a living person these fade very
00:03:55
quickly
00:03:56
in this case these are postmortem
00:03:58
pressure marks
00:04:00
they don't tend to fade because the
00:04:02
the color comes as the blood leaks out
00:04:05
of the vessels by gravity after death
00:04:08
and it more or less outlines the area of
00:04:11
pressure and then it stays that way
00:04:13
indefinitely until the body decomposes
00:04:15
the mouser's telephone records yielded
00:04:18
the first clue
00:04:20
despite the fact jenna was told not to
00:04:22
use the telephone she called several
00:04:25
friends that morning yeah you should
00:04:27
talk to him really senior well you'll
00:04:30
see on monday
00:04:31
around 11 30 jenna's conversation with
00:04:34
her friend ended abruptly hello
00:04:37
jenna
00:04:39
jenna one of the last people that she
00:04:40
speaks with
00:04:41
says that the phone goes dead jenna
00:04:43
doesn't call back the friend pages her a
00:04:46
couple of times jenna never calls back
00:04:50
police found jenna's diary in her
00:04:52
bedroom
00:04:53
which had an entry from the morning of
00:04:55
her murder
00:04:57
dear journal sorry i haven't written you
00:04:59
but i've been pretty busy
00:05:01
things have been going pretty good at
00:05:02
school except for the fact that guys
00:05:04
don't even know i'm alive half the time
00:05:08
the diary expressed a specific interest
00:05:10
in two boys
00:05:12
one was considerably older than jenna a
00:05:15
boy she met at a local amusement park
00:05:18
he was a young man about 18 or 19 years
00:05:21
old
00:05:22
who was preying on
00:05:26
children
00:05:27
that were not age appropriate
00:05:31
he was older than us um
00:05:34
not not the best kind of person that
00:05:37
you'd probably want to want to be with
00:05:39
but
00:05:40
he
00:05:41
there was something that she saw on him
00:05:43
that attracted her to him
00:05:46
investigators needed to start checking
00:05:48
alibis
00:05:49
and there was one
00:05:51
that almost defied belief
00:05:54
[Music]
00:05:58
the mauser family had planned a
00:06:00
traditional funeral service for their
00:06:02
fourteen-year-old daughter jenna
00:06:05
until her friend sarah hollander told
00:06:07
them about a conversation the two once
00:06:10
had about funerals we got on the topic
00:06:13
of funerals and she did not want her
00:06:16
funeral to be a sad thing
00:06:18
she doesn't like it when people are sad
00:06:20
she loves to make people happy
00:06:21
she loves to make people laugh
00:06:24
and so she definitely did not want her
00:06:26
funeral to
00:06:27
to portray something that she wasn't
00:06:30
about
00:06:30
so the mousers allowed sarah to help
00:06:33
plan the funeral service
00:06:36
one that was closer to jenna's wishes
00:06:39
doug mouser took his stepdaughter's
00:06:42
death particularly hard
00:06:44
he had raised jenna since she was two
00:06:46
years old and treated her like his own
00:06:49
she truly did have a great relationship
00:06:52
with him and loved him and he loved her
00:06:54
he was very active in her life
00:06:57
in the search for jenna's killer
00:07:00
investigators looked inside the mousers
00:07:02
home
00:07:03
but found no clues
00:07:06
everything was basically in its place
00:07:08
nothing knocked over or anything to
00:07:09
indicate that that jenna was fighting
00:07:11
and screaming as she went out the door
00:07:14
this raised the possibility that jenna
00:07:16
left home voluntarily
00:07:19
what the sheriff's department did was
00:07:21
try and identify any boys she might have
00:07:23
known or maybe if um boy she might have
00:07:25
left the house with even though she was
00:07:27
grounded maybe she'd get in a car with
00:07:29
them and drive away
00:07:31
police were able to identify the two
00:07:33
boys jenna mentioned in her diary both
00:07:36
had alibis for the day of the murder
00:07:39
so police turned their attention to the
00:07:41
whereabouts of janna's family members
00:07:45
jenna's 18-year-old brother jaron had a
00:07:48
solid alibi
00:07:50
neighbors have him placed there for an
00:07:52
hour hour and a half or so
00:07:54
and that's the time period where jenna
00:07:56
disappears
00:07:57
jenna's mother kathy was teaching an
00:07:59
aerobics class at the local gym so her
00:08:01
alibi checked out too
00:08:03
jenna's stepfather doug said he went to
00:08:05
work for a few hours
00:08:07
when police tried to verify his alibi
00:08:10
they discovered the security cameras at
00:08:12
doug's office were turned off that day
00:08:15
when he went into the lab he's got to go
00:08:17
through a security gate where all the
00:08:19
cars that are coming in are cleared
00:08:22
initially the person who was in the
00:08:24
booth at the time said they didn't
00:08:25
remember seeing him or his car come
00:08:27
through doug mauser could give no
00:08:29
description of the security guard and
00:08:31
for a man who'd worked at the lab for a
00:08:32
number of years you would think he would
00:08:33
know the security guards remember them
00:08:36
be able to give some description he
00:08:37
could not so doug provided a second
00:08:40
alibi that he bought lunch at a local
00:08:43
fast food restaurant
00:08:44
coincidentally
00:08:46
the restaurant's security cameras
00:08:48
weren't working either
00:08:51
if he didn't have bad luck he would have
00:08:53
no luck at all
00:08:56
i can't really imagine
00:09:01
you going into places that are supposed
00:09:03
to have video cameras and none of them
00:09:06
record you
00:09:08
it was sort of exasperating because of
00:09:10
snafu's if you will you know
00:09:13
we didn't have any tapes we didn't have
00:09:15
any solid stuff to show that he was
00:09:17
there
00:09:18
when police looked in doug's car they
00:09:20
found no blood or any evidence
00:09:22
suggesting foul play
00:09:25
and there was no evidence the car had
00:09:27
recently been cleaned
00:09:29
but underneath the car
00:09:32
investigators found something trapped in
00:09:35
the undercarriage
00:09:37
there was a significant quantity of this
00:09:39
dried plant material some of it very
00:09:41
large pieces
00:09:42
and those were removed
00:09:45
and analyzed later but
00:09:47
had this plant material been there for
00:09:49
weeks it you certainly wouldn't expect
00:09:51
to find such large pieces of it still
00:09:53
attached to the undercarriage
00:09:55
could these dried weeds tell
00:09:58
investigators anything
00:10:00
about jenna's murder
00:10:06
doug mouser told police he was the last
00:10:09
person to leave the house on the morning
00:10:11
his stepdaughter went missing
00:10:14
he claimed jenna was cleaning her
00:10:16
bedroom and he left there was no
00:10:18
physical evidence that linked him
00:10:21
you know like hair samples or dna or
00:10:24
anything like that
00:10:25
there were no physical evidence
00:10:28
none there was zippo zero nil nada
00:10:31
nothing yet investigators found some
00:10:34
suspicious plant material underneath
00:10:36
doug's car
00:10:38
which they sent to forensic botanist dr
00:10:41
fred ruscha he identified the usual
00:10:44
specimens you'd expect to find
00:10:46
underneath the car grass dirt and debris
00:10:50
but he also found
00:10:52
large quantities of yellow star thistle
00:10:55
a weed
00:10:56
i saw the yellow star thistle and then i
00:10:59
saw the small scraps that had been taken
00:11:01
off the body and i was able to compare
00:11:03
that to material that had been collected
00:11:06
from the area around the body and also
00:11:08
from the trees that were in the
00:11:09
overstory above the canyon where the
00:11:11
body was found
00:11:13
dr russia was looking for what botanists
00:11:15
call
00:11:16
diagnostic characteristics unique
00:11:19
aspects of the plant that differentiate
00:11:21
it from others of the same species
00:11:24
every plant has a life cycle and a life
00:11:27
sequence
00:11:28
early in the season they look different
00:11:30
than they do late in the season and
00:11:32
prior to
00:11:33
death
00:11:34
plant materials all species go through a
00:11:37
sequence of developmental events
00:11:40
dr ruscha discovered the star thistle
00:11:43
under doug mauser's car
00:11:45
was identical in development to the star
00:11:48
thistle found near janna's body
00:11:51
while this was significant it wasn't
00:11:54
enough to tie doug mouser to the murder
00:11:57
yellow star thistle is not a rare plant
00:11:59
it is an extremely common plant so in
00:12:02
any given area of especially of northern
00:12:04
california
00:12:06
you in low elevations a yellow star
00:12:09
thistle could be there
00:12:10
you can't show that the evidence that
00:12:13
was found underneath his car came from
00:12:15
the crime scene
00:12:16
it's too common in california and that
00:12:19
with the other flora under the car it
00:12:22
shows that he's been off-road
00:12:24
so he could have picked it up anywhere
00:12:27
investigators agreed
00:12:29
so they turned their attention
00:12:31
to the linear marks found on jenna's
00:12:34
thigh
00:12:35
the marks were made by a man-made object
00:12:37
they were clearly
00:12:39
of a shape and appearance that would not
00:12:42
be normally found in nature
00:12:44
while looking inside doug mauser's car
00:12:47
detective bosma thought he found what
00:12:49
caused them
00:12:51
the hair on the back of your neck stands
00:12:52
up and you're going this could be the
00:12:55
mark of one of the marks on her leg
00:12:57
but he didn't tell anyone about his
00:12:59
discovery instead he sent photographs of
00:13:03
jenna's skin marks to gary robertson a
00:13:06
pioneer in the field of photogrammetry
00:13:09
to see what he thought might have caused
00:13:12
them
00:13:13
robertson wanted to identify
00:13:15
the exact size of the marks down to the
00:13:19
micro millimeter
00:13:20
so he scanned every autopsy photograph
00:13:24
of the marks which enabled him to create
00:13:27
a three-dimensional model
00:13:29
we're extracting a measurement say from
00:13:31
the left photograph extracting it from
00:13:33
the right photograph and the computer
00:13:36
software merges that into a
00:13:38
three-dimensional measurement or a model
00:13:41
that we can extract and
00:13:43
do later
00:13:44
judging from the size and shape
00:13:47
robertson suspected that at least one of
00:13:50
the marks was caused by the top part of
00:13:53
a seat belt buckle
00:13:55
this was precisely what hans bosma
00:13:58
thought too
00:13:59
but he wanted robertson's independent
00:14:01
analysis
00:14:03
well normally i don't have any
00:14:04
information so i wasn't aware of
00:14:07
anything about the vehicle
00:14:09
next robertson flew to modesto
00:14:11
california to conduct an experiment in
00:14:14
doug mauser's car he wanted to try to
00:14:17
recreate the same skin pattern that was
00:14:20
on jenna's thigh
00:14:23
he placed a live model the same height
00:14:25
and weight as jenna in the back seat of
00:14:28
the vehicle over the rear seat belt
00:14:30
buckle
00:14:32
it was a hatchback
00:14:34
and one of the back seats was broken and
00:14:36
was kept flat
00:14:38
the model remained in the same position
00:14:41
for 15 minutes
00:14:43
the time it would have taken to drive
00:14:45
from jenna's house to the dump site
00:14:48
when the model was photographed
00:14:50
robertson and bosma discovered
00:14:53
what caused the other mark on jenna's
00:14:56
leg when he placed her in there
00:15:00
the
00:15:01
there's carpet on the back of that that
00:15:03
seat back because it lays flat so you
00:15:05
have a nice carpeted area the carpet
00:15:07
bead folds over as he pulls or pushes
00:15:10
her
00:15:11
over that particular area
00:15:13
and that carpet bead was what one of the
00:15:16
indentations were on on her leg
00:15:20
just to make sure
00:15:22
robertson put the model's pictures into
00:15:24
his computer and compared them to the
00:15:26
marks on jenna's leg
00:15:29
it was a virtual match
00:15:32
the beating
00:15:34
which would cause the imprint on the
00:15:36
model and on the victim's leg match
00:15:38
precisely down to microns
00:15:41
the width
00:15:42
of the carpet
00:15:44
and the orientation in that matched as
00:15:46
well
00:15:48
also the length matched
00:15:51
interestingly
00:15:52
the ripped carpet in the back seat of
00:15:54
doug's car was unusual something you
00:15:57
wouldn't find in other cars when he came
00:16:00
back and said you know it's a match boy
00:16:03
we were just ecstatic we finally
00:16:06
gonna be able to nail this guy now we
00:16:08
got him because now we can put jen in
00:16:09
that car all the pieces fit together
00:16:12
only one way and that's
00:16:14
showing
00:16:15
doug mouser guilty of killing jenna
00:16:18
they didn't feel right
00:16:20
excuse me
00:16:21
they didn't theorize
00:16:23
i'll say that on the screen i'd even say
00:16:25
it in a courtroom they didn't have
00:16:28
any theory other than he threw the body
00:16:30
he killed her and threw it over the side
00:16:33
and that she was in his car because of
00:16:35
the mark on her leg that's all there was
00:16:39
based on the forensic botany and
00:16:41
photogrammetry
00:16:44
doug mouser was arrested and charged
00:16:47
with his step-daughter's murder
00:16:53
prosecutors wondered
00:16:55
what motivated doug mouser to kill his
00:16:58
fourteen-year-old step-daughter jenna
00:17:01
how can you possibly imagine someone
00:17:03
doing something so horrible
00:17:06
i can't imagine it but it happens
00:17:08
unfortunately all the time
00:17:11
prosecutors found evidence that jenna
00:17:13
didn't always do what her parents asked
00:17:17
she saw a counselor with some regularity
00:17:19
she had oppositional defiant disorder
00:17:22
that she was
00:17:24
very defiant very aggressive very
00:17:26
confrontational with family
00:17:28
with parents the mousers telephone
00:17:31
records provided a possible clue
00:17:35
hey what are you doing i just got back
00:17:36
from the mall with annie
00:17:38
on the morning of her death
00:17:40
jenna was on the telephone violating her
00:17:42
parents rules his name's scott riley is
00:17:45
a senior
00:17:48
prosecutors believe
00:17:50
doug caught jenna on the phone
00:17:52
lost his temper
00:17:54
and struck her
00:17:56
hello
00:17:57
jenna prosecutors believe doug's
00:18:00
impulsive act of violence threatened his
00:18:02
career he couldn't risk an allegation
00:18:05
that he had hit her struck her he was
00:18:07
working at lawrence livermore lab and he
00:18:09
had a security clearance so any kind of
00:18:10
a criminal conviction on his record
00:18:12
would have been very difficult for him
00:18:14
and put his job in jeopardy with jenna
00:18:17
unconscious
00:18:18
and not sure what to do
00:18:20
prosecutors think doug panicked
00:18:23
and strangled her to death
00:18:28
he removed jenna's clothing to eliminate
00:18:31
possible trace evidence
00:18:33
when doug pushed jenna's body into the
00:18:36
back seat of his car
00:18:38
he displaced the carpet
00:18:40
the underside of the carpet and the seat
00:18:42
belt buckle left signature marks on her
00:18:45
skin that wouldn't disappear since there
00:18:47
was no blood flow
00:18:49
doug chose a dump site 15 minutes away
00:18:53
pulled his car off the road which picked
00:18:56
up the bits of star thistle
00:18:58
the same stage of development that was
00:19:01
found on jenna's body
00:19:06
[Applause]
00:19:08
[Music]
00:19:12
prosecutors think doug simply got lucky
00:19:15
when the security cameras at both his
00:19:17
office and the fast food restaurant
00:19:19
weren't working
00:19:21
but doug
00:19:22
made a crucial mistake during his
00:19:24
interrogation
00:19:26
he said he used his computer that
00:19:28
saturday at the office
00:19:30
but his employer found no evidence that
00:19:33
doug logged in
00:19:35
they couldn't find any evidence
00:19:37
whatsoever
00:19:38
that he had done to his computers what
00:19:41
he said he did basically we caught him
00:19:43
we caught him in a lie
00:19:45
doug mouser was tried and convicted of
00:19:48
second-degree murder and sentenced to 15
00:19:51
years to life in prison
00:19:54
he continues to maintain his innocence
00:20:00
ice for me this is the greatest failure
00:20:02
of my life
00:20:05
the only way i live with this situation
00:20:08
is that i did
00:20:10
the best
00:20:12
that i could
00:20:13
i did everything
00:20:15
that i could think possible
00:20:18
definitely uh jekyll and hyde
00:20:20
personality there yeah one moment he's
00:20:22
he's mr calm and cool and the next
00:20:24
moment he's seen something totally
00:20:26
different
00:20:28
i think she would be really happy to
00:20:30
know that that people love her so much
00:20:33
to to fight
00:20:35
to find the real answers to really what
00:20:37
happened to her
00:20:39
and she would be happy to know that we
00:20:41
haven't forgotten about her
00:20:43
the case against mouser was largely
00:20:46
circumstantial
00:20:48
but the photogrammetry helped convince
00:20:50
the jury
00:20:52
photogrammetry was the key element
00:20:56
and it was used to solve the case and
00:20:58
without photogrammetry
00:21:00
this case would have gone unsolved
00:21:04
[Music]
00:21:13
[Music]
00:21:18
[Music]
00:21:32
[Music]
00:21:41
you
