Forensic Toxicology In Medicine And Biology English Language Essay

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Toxicology is the branch of medicine and biology where the effects of adverse chemicals and poisons on the living organisms are studied. Forensic toxicology is defined as an examination of all aspects of toxicity that may have legal implications. It is applied in several areas in the criminal investigation. One of the areas is postmortem drug testing which is employed in death investigation to distinguish if the drugs were the cause or a contributing factor in death. Workplace drug testing is another major area where testing of biofluids (e.g. urine and blood) and hair of potential employees is conducted. Police agencies are assisted in the instances when an individual is arrested on the basis of possession of illegal and prohibited drugs with laboratory testing of those obtained material to confirm their identity.

Several kinds of drugs are tested and looked for in a toxicology lab. Some of them include opiates (cause euphoria and act as a pain reliever), amphetamines (stimulants which create excitatory state), cocaine (stimulant), Cannabinoids (e.g. marijuana- causes perceptive alterations, hallucinations and memory impairment), Phencyclidine (developed as a surgical anesthetic which produces feelings of strength, power and detachment from the world), alcohols (alter nerve-to-nerve signaling and cause behavioral changes), cyanide, carbon monoxide and other gases. An overdose of many of these drugs can cause a person's death in number of hours or sometimes even in minutes.

Specimen Collection and Testing

Blood- Blood has usually has higher concentration of toxins than other bodily fluids. Therefore, blood is preferred in DUI cases. Usually about 50-100 ml is collected from heart and peripheral site.

Urine- Due to easily obtainable large amounts and venipuncture absence, urine is preferred in pre-employment screening. It is also collected in postmortem investigation because some toxins are present in urine in larger quantities than in blood.

Gastric contents- They are beneficial in the cases where a person has suffered a sudden death due to higher concentration of toxins in stomach.

Bile and liver- the liver in involved very much any drug metabolism the bile that drains from liver can contain higher quantities of certain drugs.

Hair- Hair is an uncommon resource due to very low concentrations of drugs present but is used in pre-employment testing.

Breath- it is used predominantly in alcohol related cases because it can contain concentration up to 2100 times greater than of the blood.

Methods

Immunoassays are used due to their ability to enable reagents to react only with substances that recognize antibodies. One of the disadvantages of them is that they are highly specific for materials and need to be followed by confirmatory testing. Thin layer chromatography, though, is capable of identifying hundreds of compounds in a single run and is very inexpensive and does not require major instruments. Ultraviolet-visible spectrophotometry works on the principles of the compounds' ability to absorb UV light and produce specific spectrum for each compound to be identified. The drug to be tested is isolated or extracted from the mixture and run in a column in gas chromatography but several substances can come out at the same time causing confusion. But GC-MS can be useful in such instances being more accurate than GC because in addition it produces a unique mass spectrum of every molecule. Liquid chromatography- mass spectrophometry just uses liquid solvent instead of gas stream used in GC-MS.

Metals on the other hand are analyzed with different set of techniques. Colorimetric tests can differentiate any metal and are inexpensive but are very old and need large specimen quantity. Atomic absorption spectrophotometry, in which metal ions in solution are reduce to an atom whose valence electrons jump to high energy state when excited by an energy source and emit light which is detected for frequency, is very popular. ICP-MS (Inductive coupled plasma-mass spectrophometry) is the most modern technology which separates the atoms of the specimen by their mass and charges.

Case Studies

Rossum v. Patrick

When Rossum met de Villers in early 1995, she was abusing methamphetamine. He helped her to stop using the drug, and they married in June 1999.While in college in 1997, Rossum began working at the OME. After graduating summa cum laude with a degree in chemistry, Rossum was hired by the OME as a toxicologist in March 2000. Around the time that the OME hired Rossum, it appointed Michael Robertson to the position of Forensic Laboratory Manager. Robertson, an Australian citizen, had not previously worked for the OME. He replaced Russ Lowe, a longtime OME employee who had been serving as acting laboratory manager. Rossum and Robertson-who, like Rossum, was married at the time-began having a sexual relationship in June 2000. Several OME employees suspected the affair. At trial, Lowe and OME toxicologist Catherine Hamm testified that some of Rossum's coworkers resented her for it, believing that she might receive special treatment from Robertson, who was her supervisor.

Rossum resumed using methamphetamine in October 2000. On Thursday, November 2, 2000, de Villers confronted her about his suspicions-that she was using drugs again and worse, that she was having an affair with Robertson. He demanded that she resign from the OME and threatened that if she did not, he would reveal her drug use and her affair to her employer.

Rossum testified that when de Villers awoke on the morning of Monday, November 6, he seemed "out of it"; his speech was slurred. She called his workplace at 7:42 a.m. and left a voicemail message stating that he was ill and probably would not come to work that day.

Rossum went to work at 8:00 that morning; coworkers saw her crying in Robertson's office an hour later. The manager of her apartment complex observed her running into her apartment at 12:10 p .m. At 12:41 p.m., Rossum purchased several items at a grocery store. According to Rossum, she returned to her apartment and ate lunch with de Villers. She testified that when she asked him why he had been so "out of it" that morning, he told her that he had taken some of her oxycodone and clonazepam, which she had obtained years earlier when she was trying to end her methamphetamine addiction. She testified that de Villers went back to bed after lunch.

Rossum returned to work, but left again at 2:30 p.m. The manager of her apartment saw her car in the parking lot of the complex at 2:45 p.m. She met with Robertson later that afternoon and stayed with him until about 5:00 p.m., when she returned to her apartment. She left her apartment again at about 6:30 p.m. to run some errands and returned home at about 8:00 p.m. Rossum testified that de Villers still appeared to be sleeping at that time. She kissed him on the forehead and then took a bath and shower. After the bath and shower, she found de Villers to be cold to the touch and not breathing.

Rossum called 911 at 9:22 p.m. The operator told her to move de Villers's body to the floor and attempt CPR. When paramedics arrived, they found his body on the floor with red rose petals and a stem strewn around him. Rossum initially told the paramedics that he had not taken any drugs as far as she knew, but later told them that he may have taken oxycodone. De Villers was pronounced dead at the hospital at 10:19 p.m. While at the hospital, Rossum told a nurse that de Villers may have overdosed on oxycodone.

Dr. Brian Blackbourne, the San Diego County Medical Examiner, performed de Villers's autopsy. He determined that de Villers had been dead for at least an hour before the paramedics arrived. He testified that de Villers had developed early bronchopneumonia, a condition that results when secretions that are normally removed by the breathing process accumulate in the lungs. It occurs when a person is "unconscious or not breathing very deeply." Dr. Blackbourne also noted that de Villers had approximately 550 milliliters of urine in his bladder, which was a significant amount and would have been "very uncomfortable" to a conscious person.

The combination of the bronchopneumonia in de Villers's lungs and the amount of urine in his bladder led Dr. Blackbourne to conclude that de Villers had been immobile and not breathing properly for approximately six to twelve hours prior to his death.

Lloyd Amborn, the operations administrator of the OME, decided that an outside laboratory should perform the toxicological tests on the autopsy specimens taken from de Villers's body to avoid any potential conflict of interest. This was the first time Amborn had used an outside agency to conduct such tests.

After the autopsy, de Villers's specimens were supposed to be taken to the sheriff's office, which would then transfer them to the outside toxicology lab for testing. The specimens were placed in a cardboard box, with each individual container marked as a sample taken from de Villers's body. Because the individual at the sheriff's office who was supposed to receive the samples was not immediately available to take possession of them, the box was taken to the OME. The specimens remained in a refrigerator at the OME for approximately thirty-six hours and were then transported to the sheriff's crime lab on the morning of Thursday, November 9, 2000.

While the autopsy specimens were at the OME, anyone with a key to the building had access to them. The containers were not sealed; their tops could be pulled off and then replaced. Indeed, on Wednesday, November 8, 2000, Robertson commented to one of the toxicologists at the OME that he had looked at a sample of de Villers's stomach contents.

That same day, November 8, Russ Lowe-the veteran OME employee who served as acting laboratory manager before Robertson was appointed-called the police to report Rossum and Robertson's affair. In its closing argument, the prosecution characterized Lowe's call as a turning point that focused the police's attention on the possibility of foul play.

Toxicology tests showed that de Villers's autopsy specimens contained extremely high concentrations of fentanyl, as well as a smaller amount of clonazepam and a trace level of oxycodone. At Rossum's trial, Dr. Blackbourne testified that the concentration of clonazepam found in de Villers's blood was at the high end of what would be considered a therapeutic level, but that it was "not an overdose level" and "not fatal." He conceded, however, that sometimes postmortem testing reveals a lower concentration of a drug than had previously been present in the body. As a result of such postmortem redistribution, what was a fatal concentration of a particular drug at the time of a person's death could be measured as being within the therapeutic range at the time of autopsy. The jury also heard testimony that oxycodone, which is an opiate, and clonazepam, a benzodiazepine, can have a "synergistic" effect on each other, meaning that each drug is made more powerful when taken with the other.

The discovery of fentanyl in de Villers's samples was significant and unexpected. Fentanyl is a synthetic opiate that is roughly 100 to 150 times more powerful than morphine. At the time of de Villers's death, the OME did not ordinarily test samples for fentanyl since it is not a regularly abused drug. However, Pacific Toxicology, the outside laboratory to which the samples were first sent, tested for fentanyl as part of its standard "drugs of abuse" screen. After receiving the test results from Pacific Toxicology, Dr. Blackbourne concluded that de Villers died of acute fentanyl intoxication.

Prior to Rossum's trial, de Villers's samples were also sent to two other laboratories for testing: the Alberta Office of the Chief Medical Examiner in Canada and Associated Pathologist Laboratories in Las Vegas, Nevada. As the following chart demonstrates, the concentration levels of fentanyl measured by the different laboratories varied considerably:

 

Alberta Office of the Chief Medical Examiner

Pacific Toxicology Laboratories

Associated Pathologist Laboratories

Stomach Contents

201 ng/mL, 210 ng/mL

286.5 ng/mL, 329.7 ng/mL

128 ng/mL

Urine

_____

189 ng/mL

236 ng/mL

Blood

_____

57.3 ng/mL

32.8 ng/mL

Peripheral Blood

_____

11.2 ng/mL

_____

Antemortem Blood

_____

35.8 ng/mL

_____

Right Proximal Forearm Ulnar Aspect Tissue

_____

21.3 g

____

Key: "g" is grams; "ng" is nanograms; "mL" is milliliters; "_____" indicates that there are no results in the record

At Rossum's trial, the prosecution called Dr. Theodore Stanley as an expert witness on the properties and characteristics of fentanyl. Dr. Stanley testified that fentanyl is a potent and generally fast-acting pain reliever. The drug has one serious side effect; it can cause a person to stop breathing. Dr. Stanley testified that fentanyl begins to affect respiration at a concentration level in the blood of 2 ng/mL. At a concentration of 4 ng/mL, about half of "opioid naive" individuals-people without significant experience taking opiates-would be breathing very slowly or not at all. At 57 .3 ng/mL, the concentration found in de Villers's blood by Pacific Toxicology, no opioid-naive individual would be conscious or breathing.

Dr. Stanley testified that the speed with which fentanyl takes effect depends on the manner in which the drug is administered: the peak effect occurs about sixteen hours after administration of a transdermal patch, twenty to thirty minutes after oral consumption, fifteen to twenty minutes after intramuscular injection, and five minutes after intravenous injection. He explained that fentanyl is not normally administered orally because when the drug is taken in this way, the liver destroys about 65 percent of it, leaving only about 35 percent to enter the bloodstream.

None of the three physicians who testified at Rossum's trial-Dr. Blackbourne, Dr. Stanley, or the defense expert on fentanyl, Dr. Mark Wallace-could provide a definitive opinion as to how the fentanyl was introduced into de Villers's body. Dr. Stanley, however, testified that the differing concentration levels in de Villers's system, along with the evidence indicating that de Villers had been unconscious and breathing shallowly for hours before his death, suggested that fentanyl likely had been administered to de Villers on multiple occasions.

After de Villers's death, the OME audited its impounded drugs and drug standards. It discovered that fifteen fentanyl patches and ten milligrams of fentanyl standard were missing. Rossum had logged in the fentanyl standard and had worked on each of the three cases in which the missing fentanyl patches had been impounded. The OME also determined that quantities of methamphetamine, clonazepam, and oxycontin (a time-released form of oxycodone) were missing.

Rossum's Trial and Post-Trial Proceedings

Rossum was prosecuted for the murder of de Villers with the special circumstance that the murder was committed by means of poison. Her jury trial began in October 2002. At trial, the prosecution argued that Rossum poisoned de Villers with fentanyl, possibly after she gave him clonazepam but the clonazepam failed to kill him. The defense conceded that fentanyl caused de Villers's death but contended that de Villers committed suicide because he was despondent over his marital problems.

The jury found Rossum guilty in November 2002, and in December 2002 the court sentenced her to prison for life without the possibility of parole.

On June 13, 2005, the California Court of Appeal affirmed Rossum's conviction on direct review and denied her concurrently filed petition for a writ of habeas corpus. The California Supreme Court summarily denied her petition for review of her direct appeal.

On December 15, 2006, Rossum filed a petition for a writ of habeas corpus in the California Supreme Court. The petition asserted for the first time the claim at issue in this appeal-that Rossum's trial counsel rendered ineffective assistance by not having de Villers's autopsy samples tested for fentanyl metabolites despite the fact that such tests might have ruled out fentanyl as the cause of de Villers's death and thus disproven the prosecution's theory of the case. Instead, as the petition stated, counsel promptly conceded the prosecution's theory-that fentanyl was the cause of de Villers's death. Rossum supported her petition with a declaration from Dr. Steven H. Richeimer, a medical professor and practitioner with substantial experience in anesthesiology and requested an evidentiary hearing. Dr. Richeimer has overseen the administration of fentanyl on thousands of occasions and is well versed in the drug's characteristics and properties. His declaration explained that fentanyl "is a very rapidly acting drug." As a result, if very high doses were rapidly administered to de Villers, then he likely would have died "within minutes," "not in a manner consistent with the 6-12 hours of impaired breathing and consciousness described by Dr. Blackbourne." Alternatively, if de Villers absorbed fentanyl "gradually, perhaps through the stomach," then he likely would not have survived "long enough for his blood levels to reach the extremely high levels" measured by the toxicology labs.

Dr. Richeimer's declaration stated that contamination of the samples drawn from de Villers's body could explain the seeming "inconsistency between the rapid action of fentanyl, the extraordinarily high concentration levels, and the lengthy period of impaired breathing and reduced consciousness" that de Villers suffered. Indeed, Dr. Richeimer opined that contamination of the specimens would explain the high blood levels better than ingestion or other administration of fentanyl to the decedent....In attempting to determine if the cause of death was from fentanyl, it would be necessary to rule out the possibility that the samples were contaminated.

According to Dr. Richeimer, a toxicology lab could conclusively determine whether fentanyl was present in de Villers's body at the time of his death by testing his samples for metabolites of fentanyl. If de Villers's specimens contain metabolites of fentanyl, then fentanyl must have been present in his body at the time the specimens were taken. If no metabolites are present, then the specimens must have been contaminated after his death.

Source:

http://campus.westlaw.com.ezproxy.stockton.edu:2048/result/default.wl?rltdb=CLID_DB86803314216279&srch=TRUE&db=ALLFEDS%2cALLSTATES%2cSCT&sv=Split&service=Search&eq=Welcome%2fCampusLaw&fmqv=s&rs=WLW10.08&method=TNC&action=Search&query=(TOXICOLOGIST)+%26+(DRUG)&mt=CampusLaw&fn=_top&origin=Search&vr=2.0&rlt=CLID_QRYRLT29819324216279&rp=%2fWelcome%2fCampusLaw%2fdefault.wl&ifm=NotSet&cfid=1&sp=stockton-2000

Williams v. State

Frederick Williams was stopped at a field sobriety checkpoint. After failing a series of field sobriety tests, he was given a breath test which registered an alcohol level of 0.07, just below the legal limit of 0.08. Two police officers trained as drug recognition experts then asked the defendant to take a Drug Influence Evaluation test (DIE), because the breath test result was not consistent with their observations of the degree of impairment. Based on the results of the DIE, the officers concluded the defendant was under the influence of alcohol, a central nervous system stimulant, and cannabis. The officers then arrested the defendant for driving under the influence. The defendant's urine sample tested positive for marijuana metabolite and cocaine.

At the hearing on the motion, the State presented testimony which explained that a certified drug recognition expert ("DRE") receives specialized instruction to learn the twelve step evaluation for conducting the DIE. The DIE basically consists of the usual DUI investigation, including the standard field sobriety tests, with the addition of a physical examination. The physical examination includes measuring pupil size and observing pupil reaction to light, taking blood pressure and pulse rate, examining the nose and mouth for evidence of drug use, and touching the arm to determine muscle tone. The information obtained by the physical exam is then recorded on a symptomatology matrix (grid chart). The various symptoms of drug use, such as an increased pulse, are matched by a process of elimination to the corresponding drug category. This grid helps to narrow the type of drugs a suspect may have in their system. Subsets of the DRE protocol include the Horizontal Gaze Nystagmus test ("HGN"), Vertical Gaze Nystagmus test("VGN"), and the Lack of Convergence test ("LOC"). The State submitted numerous studies and articles, including testimony from several doctors, supporting the reliability of the DIE protocol. The drug evaluation and classification consists of the following twelve steps:

Breath Alcohol Test. A breath alcohol test is administered to rule out alcohol intoxication. The drug influence evaluation will not be conducted if the breath test result is consistent with the degree or type of impairment.

Interview with Arresting Officer. The arresting officer interviews the defendant to ascertain whether the defendant gave any statement and to ascertain whether any drugs or drug paraphernalia were found in the defendant's possession.

Preliminary Examination. The defendant is questioned about his or her medical history and examined for signs of illness or injury. The defendant's eyes and pupils are checked for serious trauma and to see if the eyes are bloodshot or retracted. At this time, the first of three pulse rates is taken.

Eye Examination. The following tests are administered: the Horizontal Gaze Nystagmus test ("HGN") (rapid involuntary horizontal oscillation of the eyes when attempting to follow a target moved from side to side); the Vertical Gaze Nystagmus test ("VGN")(inability to smoothly track the up-and-down progress of a stimulus); and the Lack of Convergence test ("LOC")(inability to cross eyes to focus on a target directly before the eyes).

Field Sobriety Test. A second field sobriety test is conducted which includes the Romberg Balance Test, walk and turn test, one leg stand, the finger to nose test, and the HGN test.

Vital Signs. Blood pressure, temperature, and a second pulse rate are taken using the standard sphygmomanometer, stethoscope, and thermometer.

Darkroom Examination. The defendant's pupil size is measured in four different lighting conditions using a pupilometer. Oral and nasal cavities are also examined for signs of ingestion.

Physical Examination. The defendant's muscle tone is examined for signs of flaccidity or rigidity which could indicate use of alcohol or certain drugs.

Injection Sites Check. Arms, wrists, ankles, etc… are checked for signs of injection indicating possible drug abuse. A third pulse rate is also taken at this stage.

Post Miranda Interrogation. Once the evaluator reaches this stage and determines that the defendant is under the influence, the defendant is questioned about any history of surgery or other medical condition.

DRE Opinion. The evaluator forms an opinion as to whether the defendant is under the influence of a certain category of drugs.

Toxicological Examination. A toxicological examination is administered to confirm the presence of the drug.

In this case, the arresting officer was also a certified Drug Examiner. He conducted the twelve-step Drug Evaluation. In the interview portion, the defendant was cooperative, told the officer that he had had a couple of beers, and also revealed that he had consumed marijuana several days ago. He conceded that he was "maybe a little" under the influence.

APPENDIX

INDICATORS CONSISTENT WITH DRUG CATEGORIES

 

DEPRESSANT

STIMULANTS

HALLUCINOGEN

PCP

HGN

PRESENT

NONE

NONE

PRESENT

 

VERTICAL

PRESENT

NYSTAGMUS

(HIGH DOSE) *

NONE

NONE

PRESENT

 

LACK OF

CONVERGENCE

PRESENT

NONE

NONE

PRESENT

 

PUPIL SIZE

NORMAL (1)

DILATED

DILATED

NORMAL

 

REACTION TO

LIGHT

SLOW

SLOW

NORMAL (3)

NORMAL

 

PULSE RATE

DOWN (2)

UP

UP

UP

 

BLOOD

PRESSURE

DOWN

UP

UP

UP

 

BODY

TEMPERATURE

NORMAL

UP

UP

UP

 

* high dose for that particular individual

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