by jane on Fri Jul 20, 2012 2:03 pm
According to the appellate brief, the prosecution did not prove the connection between Scott's fishing route and the location where the bodies were found. IMO, this is a very compelling argument:
See pp 266-296 in the brief for more detail. This is just some of the significant information:
IX. THE TRIAL COURT VIOLATED BOTH STATE AND FEDERAL LAW BY
ADMITTING EXPERT “SCIENTIFIC” EVIDENCE, BASED ON WHERE
CONNER’S BODY WAS FOUND, TO INFER THAT CONNER WAS
PLACED IN THE WATER WHERE MR. PETERSON HAD BEEN FISHING.
>>>>>
The prosecution’s theory was that Mr. Peterson put Laci Peterson into the bay near
where he was fishing. But apart from the erroneously admitted and flawed dog-scent
evidence (see Argument VI, supra), there was no forensic or other evidence connecting
Mr. Peterson’s fishing trip with the bodies of Laci and Conner.
The prosecution bridged this evidentiary chasm with the testimony of Dr. Ralph
Cheng, a hydrologist employed by the United States Geological Survey. Over defense
objection, Dr. Cheng was permitted to testify that, based on the location of where Conner
was found, Conner’s body had been anchored to the bay bottom in an area 500-1000
267
yards southwest of Brooks Island. That was the approximate area in which Mr. Peterson
said he was fishing on December 24. (55 RT 10725-10728.)
The import of this evidence is obvious. It literally “connected the dots” between
Mr. Peterson’s boat and Conner’s body. Echoing the precise refrain he had used with the
dog scent evidence, the prosecutor told the jury that if Dr. Cheng was believed, “then that
man's a murderer. It's as simple as that.” (109 RT 20279-20280.)
>>>>>>>>>>>>
>In short, while the trial court may have been correct that the science of tidal
movement is well established, that is not what Dr. Cheng was testifying about. Instead,
he testified about something new and quite different, i.e., the physics of the movement of
objects in the waters of the bay. Unlike HGN, there was no history of the use of this in
forensics, with or without studies; it was both unproven and new. Dr. Cheng’s testimony
about the movement of bodies in water was thus a novel scientific theory which should
not have been introduced unless the state met the requirements of People v. Kelly.
There was, moreover, a further reason Dr. Cheng’s testimony could not meet the
Kelly test. The second prong of Kelly requires that, “[i]n addition to general acceptance,
the proponent must also establish that the witness testifying as to general acceptance is
“properly qualified as an expert to give [such] an opinion.” (People v. Stoll, supra, 49
Cal.3d at p. 1155.) By his own admission in court, Dr. Cheng’s expertise did not extend
to the physics of the movement of large objects in bodies of water -- to what kinds of
objects, and what weights, will be moved by currents in the bay, and how far. (See 100
RT 18865; 101 RT 18926-18938 ) Quite to the contrary, Dr. Cheng candidly admitted,
“Well, I’m not – I’m not the expert in that area here. I don’t know how the body is
behaving in water.” (101 RT 18925.) The prosecution thus established neither that such
a body of scientific information regarding the physics of the movement of large bodies in the water exists, nor that Cheng was capable of using it to form an opinion even if it did.
The admission of Dr. Cheng’s testimony violated state law.
>>>>>>>>>
Dr. Cheng continued that while he knew precisely where the body landed, “we
didn’t know when the body precisely landed at that location. Therefore, in order to
reconstruct where the body started moving from, certain position in the bay, still involves
some uncertainty.” (Id., emphasis added.)
With all due respect, the phrase, “some uncertainty,” is something of an
understatement. Even if Dr. Cheng was entirely correct about how fast the body was
moving in the water, without knowing both when the body started moving, and when it
stopped (that is, when it landed), it is impossible to determine where it originated from by
relying on how fast the body was moving.
Here, Dr. Cheng hypothesized that the body was freed of restraints on the sea floor
during a storm that occurred on April 11th through April 12th. (101 RT 18896-18899,
18912.) But Dr. Cheng testified that the storm lasted for 18 hours. (101 RT 18896.)
Under Dr. Cheng’s own hypothesis, the bodies could have begun moving at the beginning
of the storm or at the end of the storm. Because there was enormous uncertainty as to
when the bodies began to travel, it was impossible for Dr. Cheng to conclude how far
they traveled before they made landfall.
>>>>>>>>>
But even putting aside questions as to Cheng’s thesis for when the bodies began to
move, there is equal uncertainty as to when the bodies stopped moving. Conner’s body
was found at around 4:30 p.m. on April 13, 2004. (61 RT 11905.)48 But that does not
mean that is when the body actually landed on the beach. If the body arrived on shore 24
hours before being found on April 13th, it would have been traveling for a significantly
shorter prior of time than Dr. Cheng assumed, and would necessarily have traveled a
much shorter distance than Dr. Cheng concluded. On the other hand, if the body arrived
on the shore at or near 4:30 p.m. on April 13th, it would have been in the water (and
traveling) a much longer time, and would necessarily have originated from a point much
farther away. In that scenario, the body would also have been subject to different winds
and currents over the extended time it was traveling, and thus the direction from which it
came would have been different. In either scenario, the body would not have originated
from the area where Mr. Peterson had been fishing: it could have come from an area
much farther away than Brooks Island, or from an area very close to the shore on which
the body was found.
>>>>>>
In short, the reliability of Dr. Cheng’s testimony regarding Conner’s body thus
depended on two variables for which there was no proof whatsoever: the time the body
began moving in the water, and the time it stopped. It also depended on another variable
about which Dr. Cheng really knew nothing: the distance and direction in which the
currents might carry an object such as Conner’s body.
The matter was even more unreliable as to the trajectory of Laci’s body. Indeed,
the number and degree of variables regarding her body were so extreme that Dr. Cheng
himself admitted he could not draw any reliable conclusion with respect to her trajectory: In the end, even Dr. Cheng admitted that, because he was forced to make assumptions
regarding timing (assumptions he did not have the expertise to make), his conclusions
featured “large uncertainties.” (101 RT 18931.)
Faced with similar uncertainties and uncontrolled variables underlying scientific
testimony, courts have not hesitated to rule such testimony inadmissible under People v.
Kelly.>>>>>>>>>>
In precisely the same way, Dr. Cheng’s analysis was fraught with uncertainty from
the large number of uncontrolled variables. For this reason alone, the prosecution failed
to carry its burden of proving that Dr. Cheng’s testimony followed any generally accepted
scientific procedure. Dr. Cheng made unfounded assumptions about when the body
started moving. He made unfounded assumptions about when the body stopped moving
by arriving on shore. As a result, Dr. Cheng did not take into account what other wind
and current variables would have come into play if his timing assumptions were wrong.
That is, if he was wrong about how long the body was in the water, he could not
accurately predict how far the body would travel or the direction it would come from,
since the winds and currents (which are important under Cheng’s thesis for determiningdirection) change the more time the body is in the water. Further, because Dr. Cheng
admitted that he was not an expert at all in the movement of bodies in water (101 RT
18925-18926), he could not factor into his analysis how the shape and size of a body
would impact his conclusions. The failure of Dr. Cheng’s model to account for the
variable of the shape and size of the body moving through the water is fatal to any
conclusion he might reach as to the movement of the bodies in the bay.
>>>>>>>>