Underwater Forensic Investigation

Ronald F. Becker, Stuart H. Nordby, Jon J.

• Publisher: CRC Press
• Year: 2013
• ISBN:
  9781482210026
• Edition: 2
• Topic: Diritto
• Subtopic: Diritto penale

The evidence discovered at underwater crime scenes must be handled with the same attention to proper chain of custody procedures as with any other type of investigation. Improper handling of these scenes can lead to evidence being lost, unrecognizable, destroyed, contaminated, or rendered inadmissible at the time of trial. Updated and expanded, Und

Introduction

1

New Words and Concepts

enriched air nitrox

fsw

University of California at San Diego

Chaminade University of Honolulu

search integrity

background contamination

barrel blowback

public safety diver

salvaging

Texas State University

black water diving

recovery myths

hand searches

Student Learning Outcomes

On completion of this chapter, students will be able to

Describe the evolution of public safety diving

Explain the common myths associated with underwater investigations

Recognize that there is more than one way to obtain a successful underwater recovery result

Man and the Sea

More than 70% of the earth’s surface is covered with water. Since earliest time, humans have been drawn to the earth’s waters for trade, transportation, recreation, and food. Greeks, as early as 4500 BC, were free diving in the Mediterranean. Accounts of Herodotus, the Greek historian, describe the efforts of free divers in salvaging sunken treasure (Diolé, 1951). Entry into the underwater realm was undoubtedly linked with the transit of goods by vessel. Ocean trade and war gave rise to the need for salvage activities. Free diving was limited in depth and duration. It was inevitable that efforts would be made to use “machines” to allow divers to increase both depth and duration (efforts that have yet to cease). Aristotle wrote in 330 BC of divers using a diving bell made of leather and later of pitch-bound wood (Diolé, 1951).

Today, divers using compressed air can safely dive unfettered to depths in excess of 100 feet. With the quest for deeper or longer still fresh in our collective memories, recreational divers are flocking to dive shops for advanced instruction in using mixed gases primarily “enriched air nitrox” (EAN). Increasing the percentage of oxygen in a compressed air tank from the normal 21% oxygen (79% nitrogen) upward to as much as 40% oxygen (60% nitrogen) reduces the amount of nitrogen being absorbed by the body at depths below 33 feet, allowing longer dives with a reduced fear of decompression sickness (nitrogen coming out of solution or the “bends”). Breathing enriched oxygen at a depth not to exceed 100 fsw (feet seawater) has proven to be safe, presuming the diver using the mixture has had the appropriate accompanying training.

Since 1980, technology and education have moved diving from the purview of the strong and courageous and placed it in the world of recreation and sport.

The popularizing of wartime diving by the media gave rise to a national curiosity about navy “frogmen” and to a 1960s television program called Sea Hunt and starring Lloyd Bridges as Mike Nelson, ex-navy frogman. Interest increased with the Jacques Cousteau television specials and a James Bond film starring Sean Connery, Thunderball. People were no longer content watching others dive. Sport diving was born, and its popularity has continued to grow.

In the world of science, underwater archaeology is in its infancy. Many archaeologists were interested in employing scuba equipment and scuba diving in the unearthing and recovery of submerged archaeological artifacts. These pioneers were convinced they could employ acceptable scientific archaeological field principles underwater. Many archaeologists were of the opinion that marine archaeology would never meet the rigors of the science of archaeology. Critics viewed early underwater archaeological activity as a salvaging or looting of artifacts. They were convinced that those involved in these operations were opportunists and treasure hunters who were not properly handling, processing, or preserving the artifacts that they were recovering or would recover (Catambis, Ford, and Hamilton, 2011). There was a concern that no information was being gathered from the artifacts or their resting place.

It is the field archeologist’s belief that it is his or her responsibility to record the location of each artifact or piece of artifact because, as in a criminal investigation, what may have little relevance or significance now may prove invaluable later. It took time and attention to detail, but a slowly evolving science emerged from the watery depths by applying the same techniques that field archaeologists applied. The underwater archaeologist is in every sense of the word an underwater investigator.

These individuals now have the keys to unlock the richest museum in the world. Utilizing excavation techniques similar to those used in land excavations, these emerging scientists have been able to recover artifacts from sunken cities and reconstruct much of those cities’ history and culture. They have been able to excavate entire vessels and, from their cargoes, deduce place of origin, trade routes, and personal information about crew and passengers.

It was not until 1974 that academe was ready to embrace scuba diving as an appendage of archaeological fieldwork. In that year, the University of California at San Diego became the first to offer an undergraduate degree in underwater archaeology. It is the purpose of this text to employ marine archaeological techniques in police underwater operations whenever possible and whenever such application will preserve submerged evidence.

The world of underwater forensic investigation is as new today as was marine archaeology in 1974. Many of the obstacles that marine archaeologists had to contend with then, underwater investigators are revisiting today. As you will discover in succeeding chapters, fire departments have historically provided recovery divers for police purposes. In some instances, that precedent has been impossible to dislodge. Police administrations confronted with the proposition that fire departments may not be adequately prepared for handling evidence have chosen to ignore the evolution of underwater investigation. That ignorance is often based on budget considerations. Building, properly equipping, and training an underwater recovery team of underwater investigators is expensive and labor intensive. Why absorb the costs associated with creating a new specialty when the fire department is ready, willing, and able to continue providing the same service, free of charge, to the police agency? The answer is the reason this book exists: so that homicides and other crimes do not go undetected or uninvestigated. A more insidious reason exists within some agencies: By recognizing underwater forensic investigation and investigators, agencies would be forced to acknowledge that they have not been as diligent in investigating criminal activity in the past as perhaps they should have. Ignorance in this instance is a way to avoid community umbrage.

In June 2003, Chaminade University of Honolulu was the first 4-year university to offer as part of their criminal justice curriculum a course in underwater forensic investigation. What the University of California did with marine archaeology in 1974, Chaminade University chose to do with underwater forensic investigation in 2003.

Law Enforcement and Underwater Evidence

People flock to recreational waterways in vast numbers. As the number of people using recreational waterways increases, so do the number of accidents, drownings, violent crimes, and homicides. Criminals often seek a watery repository for weapons and other evidence of wrongdoing. It has become an integral part of the police function to provide resources that can be deployed to retrieve this evidence. Historically, fire departments have provided these services to the police since they already had firefighters who were trained in search-and-rescue diving. It was believed that no special skills other than diving were required to recover underwater evidence. The handling and processing of underwater evidence was a salvage operation.

The first accounts of a dedicated (specific regarding function) police underwater recovery team appeared in Dade County, Florida. The Dade County Underwater Recovery Unit began in 1960 and has had the responsibility for 28 cities, 400 miles of inland canals, over 400 rock quarries, and 75 miles of bay front (Robinson, 1969).

As we view existing dedicated dive recovery operations, it is apparent they have evolved and been criticized much the same as early underwater archaeologists. Police recovery of underwater evidence could also be criticized for an absence of scientific rigor, focusing on salvage rather than recovery and reconstruction.

What information is lost in the salvage process? What might be inferred from measurement, sketches, and photographs, if not at the time of discovery, perhaps later? What parts of the story remain untold because of a failure to connect the evidence with the defendant? If a piece of evidence were located on land, no competent investigator would pick it up; hold it over his head and say, “I’ve found it.” Contrary to popular belief, forensic evidence is not necessarily lost when it has been immersed in water.

Many nondivers and most police administrators believe that the police diver’s job is fun, much like the film footage seen on television during Discovery Channel underwater specials and in the movies (usually filmed in the Caribbean). Film footage is shot in water with visibility (viz) in excess of 100 feet. The divers are blithely soaring through the water enthralled with the sea’s abundance and diversity. The world of the underwater forensic investigator is much different from that depicted on television and in the movies, unless that depiction takes place in a quarry, cesspool, or sewage treatment settlement pond; on the bottom of some river, lake, or stagnant pond; or under the crashing surf in between the crevices of ocean rock and sand. Most underwater investigation is conducted in water with visibility less than 3 feet. That 3 feet of visibility is often turned into zero visibility when the sediment from the bottom stirred up by the diver is added to the ambient sediment that was responsible for the originally reduced visibility. This is not a place for the claustrophobic. Recovery diving is done on the bottom; there is no “soaring.” Most recovery divers lie on the bottom tethered to a tended line reaching back to shore. Additional weight is often added (a dangerous practice) to allow the diver sufficient purchase on the bottom to be able to pull against the tended line. It is this line tension that determines the quality (integrity) of the search.

When water is so limited in its visibility that divers cannot read the numbers on their depth and air pressure gauges, it is said to be “black water” diving. Black water diving does not depend on the sense of sight. In many instances, a reliance on sight when visibility is limited is detrimental, if not fatal. In a nogravity environment, without sight, how does one determine “up”? Without sight, how does a diver determine his or her depth? Without sight, how does a diver tell in which cardinal direction he is traveling? Without sight, how does a diver tell how much air is left in the tank? Without sight, how does a diver tell how long he or she has been submerged? The diver who can rely on his or her sight need not address any of these questions. Depth gauges, air gauges, compasses, watches, and computers have been the tools divers have historically relied on to provide input about their support systems and environment. The black water diver depends on his or her teammates to convey the necessary information to him or her. The dry land investigator can be a “lone wolf” or work with a single partner. The underwater investigator is part of an investigative work group that must coordinate their efforts not only for success but also for the survival of the investigator. More equipment is being developed as you read this to address the specific needs for the technical diving often required of underwater investigators. But, much of the technique used has been a process of trial and error, injury and death.

Touch is the sense on which the low-visibility underwater investigator must depend, although most teams use underwater metal detectors or search methods to reduce reliance on “hand searches.” The hand search is the foundation on which all underwater searches are based. Most body recoveries are hand searches. With all other senses rendered dysfunctional, the focus of sensory input is on the hands. All data on which the diver is normally dependent must reach the diver through his or her tactile senses. In underwater recovery operations, those data are often relayed by team members through tactilely sensed communications (line tugs). It is imperative that each team member trusts explicitly those who comprise the underwater investigative team. The confidence that underwater recovery team divers have in each other is literally based on “blind faith.”

In February 1994, Texas State University, San Marcos, purchased what had been Aquarena Springs theme park. The area that had been used for an underwater theater was left intact and unused. Various faculties at the university began to consider possible uses for the park and the underwater theater.

The Criminal Justice Department at Southwest Texas State University embarked on its journey into the world of public safety diver training in July 1994 with the birth of the Underwater Institute. I created and was the director of the Underwater Institute. In creating a public safety dive training institute, it was necessary to determine the state of public safety diving in Texas. It was noted that diver recovery operations were actually “salvag...