Forensic features of a fatal Datura poisoning case during a robbery

Highlights

• Datura is used for poisoning, recreation or predation.

• Datura intoxications are rarely deadly.

• The clinical presentation of Datura intoxication is anticholinergic syndrome.

• Scopolamine, atropine and hyoscyamine may be found after embalmment in Datura intoxication cases.

Abstract

Datura poisonings have been previously described but remain rare in forensic practice. Here, we present a homicide case involving Datura poisoning, which occurred during a robbery. Toxicological results were obtained by second autopsy performed after one previous autopsy and full body embalmment. A 35-year-old man presented with severe stomach and digestive pain, became unconscious and ultimately died during a trip in Asia. A first autopsy conducted in Asia revealed no trauma, intoxication or pathology. The corpse was embalmed with methanol/formalin. A second autopsy was performed in France, and toxicology samples were collected. Scopolamine, atropine, and hyoscyamine were found in the vitreous humor, in addition to methanol. Police investigators questioned the local travel guide, who admitted to having added Datura to a drink to stun and rob his victim. The victim's death was attributed to disordered heart rhythm due to severe anticholinergic syndrome following fatal Datura intoxication. This is a recent case of a rare homicide involving Datura that highlights general information on Datura and discusses forensic interpretation after a previous autopsy and body embalmment.

Introduction

Datura is a poisonous plant belonging to the Solanaceae family, which includes nine species, such as Datura stramonium (known also as “jimson weed” or “devil's weed”), Datura inoxia, and Datura ferox [1]. Datura species grow worldwide and are used as medicinal plants for the treatment of asthma or pain or as an aphrodisiac [2], [3]. The toxicity of Datura has been well described for years [4], [5] in relation to its uses for poisoning [6], recreation, and predation in robbery or rape attempts [7]. Its main toxic compounds are tropane alkaloids, including atropine, hyoscyamine (the levo-isomer of atropine) and scopolamine. These alkaloids are present in all parts of the plant. Variations in the concentrations of these three alkaloids may be observed among Datura species [8], but they are present in all of the species [9].

Atropine and scopolamine are muscarinic antagonists that cause anticholinergic syndrome, which is characterized by ocular effects (mydriasis and paralysis of accommodation), dryness of the mucosal lining (which affects the mouth, sinuses, etc.), mental disorders (excitation, agitation, confusion, delirium, hallucinations, etc.), neurological effects (colonic spasms and seizures), hyperventilation, hyperthermia, sinus tachycardia, and disordered heart rhythm [1], [7], [10].

Death is uncommon in cases of Datura intoxication, and in most cases [6], [7], complete recovery occurs after one or two days [11] with symptomatic treatment (supportive care and gastrointestinal decontamination). An acetylcholinesterase inhibitor, physostigmine, is a specific antidote to Datura intoxication [11]. Death from intoxication occurs due to respiratory depression, disordered heart rhythm or respiratory inhalation in the case of seizures [11].

Many parts of the Datura plant can be used, including the seeds (in domestic dyes), leaves (in tea, for fumigation, in craft wine, and in skin balm), and flowers (in herbal infusions) [5], [6].

The literature contains descriptions of accidental Datura intoxication, including cases caused by eating a hamburger [6], drinking homemade “moon flower” wine, which resulted in scopolamine poisoning [12], drinking Indian tonic water [13], drinking tainted comfrey tea [14] and eating honey [15], and many cases of fatal poisoning have occurred in children who were attracted by the capsules and seeds [2]. Datura is also known as a recreational drug due to its hallucinogenic and psychoactive effects [2], [4]. It can be used in several ways, such as ingestion through drinking [10], smoking [16] or chewing the seeds [17]. Datura consumption may result in chronic mental disorders, and such cases have been reported after acute or chronic intoxication [18].

Datura intoxication may also be involved in criminal activity, such as sexual assault or robbery. Sáiz et al. have described multiple uses of the scopolamine compound in Datura, such as the blowing of Datura powder into victims’ faces during sexual assaults to block their free will [7]. Uribe et al. have reported several cases of scopolamine and hyoscyamine use in robberies and rapes in Colombia [19]. To the best of our knowledge, no previous case of homicide has been described.

Datura is difficult to identify in a forensic context because tropane alkaloids are difficult to detect by gas chromatography–mass spectrometry (GC–MS) and liquid chromatography–diode array [1]. Liquid chromatography–tandem mass spectrometry (LC–MS/MS) is cited as the most effective technique for identifying these alkaloids.[1]. Moreover, the main toxicology studies analyzing tropane alkaloids have been in clinical, therapeutic or pharmacological fields [20], [21], [22], [23], [24]. Concentrations of tropane alkaloids in biological fluids after Datura consumption are rarely reported [6], [25], [26] and are even less frequently reported in forensic samples, such as viscera [6] or hair [27]. Tropane alkaloids have been detected in urine and blood in a few cases [25], [26], [28], and the rarity of these cases is likely due to the short half-lives of these compounds. Atropine has been reported to have a plasmatic half-life of approximately 4–6 h [29]. Scopolamine is rapidly eliminated during the first 24 h after intoxication [19], and its half-life has been reported to be approximately 1.5 h [30].

Recent studies have reported positive results for atropine and scopolamine in the hair of living people after chronic Datura use, as determined by ultraperformance liquid chromatography–tandem mass spectrometry analysis (UPLC–MS/MS) [1], [27], [31], [32]. These reports have introduced a new range of toxicology methods for Datura investigation.

Few studies have described tropane alkaloid detection after the death of the Datura consumer (summarized in Table 2), and only Steenkamp et al. have shown positive qualitative results for viscera (gastric content, liver, and kidneys) [6].