In 1920 the medical examiner’s office tallied 692 people killed by automobiles in New York City; five years later that number was 1,272, despite a state law, passed in 1922, that required drivers to be licensed. Both Norris and the Manhattan district attorney, Joshua Banton, had worked hard to get the licensing law passed. Their joint public position was brief and completely clear: “There are many persons driving automobiles in this city who ought not to drive.”

  THE MOTORIZED STAMPEDE pressured the federal government to resolve the risk posed by lead additives to gasoline. In January 1926 the Public Health Service released its report on tetraethyl lead, concluding that there was “no danger” in adding the compound to gasoline, and no reason to prohibit the sale of leaded gasoline as long as workers were well protected during the manufacturing process.

  The scientists who wrote the report had been recruited by both the government and industry. They’d studied the risks associated with everyday exposure by drivers, automobile attendants, and gas station operators and found it to be minimal. True, all the drivers tested showed trace amounts of lead in their blood. But a low level of lead could be tolerated, the scientists believed; none of the test subjects showed the extreme behaviors and breakdowns associated with the “looney gas building.”

  Critics, even then, charged that the panel was biased, deliberately underestimating the risks. But, in fact, the conclusions weren’t entirely wrong: the extra protections recommended for industrial workers did make the factories safer. Workers exposed to TEL at lower levels did not drop to the ground or show immediate signs of ill health. Workers who were well buffered against the additive were not rushed to the hospital or strapped into straitjackets. There was no arguing with the report’s finding that safety precautions did the job.

  The federal panel did issue one cautionary note however: exposure levels would probably rise as more and more people took to the road. Perhaps at a later point, the scientists suggested, the research should be taken up again. It was always possible that leaded gasoline might “constitute a menace to the general public after prolonged use or other conditions not foreseen at this time.”

  But that was the future’s problem. In 1926, citing evidence from the TEL report, the federal government revoked all bans on the production and sale of leaded gasoline. The reaction of industry was jubilant; one Standard Oil spokesman likened the compound to a “gift of God,” so great was its potential to improve automobile performance.

  TOXICOLOGISTS like Alexander Gettler had more urgent worries about risks in the age of the automobile: focusing on other chemicals released in engine exhaust. When gasoline or any other carbon-rich fuel burned in the modern engine, a cascade of reactions resulted, atoms separating and recombining, loose carbon bonding with circulating oxygen. Those carbon-and-oxygen connections, in particular, created two differently troublesome gases: carbon dioxide and carbon monoxide.

  In general, when fuel combustion is highly efficient, the main by-product is carbon dioxide—a single carbon atom attached to two oxygen atoms. No scientist really considers carbon dioxide a poison, not in the routine sense of the word. It is a natural by-product of the human metabolic process, among other things. When people breathe, inhale air, they take in oxygen, then exhale back out carbon dioxide (created in the carbon-rich interior of humans and other animals).

  Carbon dioxide (CO2) occasionally killed directly in the 1920s, but rarely. Such deaths occurred when CO2 displaced oxygen in a tightly closed space. In transporting fruits and vegetables, for example, shippers often kept the produce cold with superchilled carbon dioxide. At about 103 degrees below zero Fahrenheit, the gas freezes to a solid, turning into glassy-looking chunks of exceptionally cold material. As the chunks warm and “melt,” they return directly to a gaseous state, giving the material the nickname “dry ice.” In an unventilated space, this seeping release of carbon dioxide will gradually replace oxygen, suffocating anyone inside.

  Five longshoremen were once found dead in the cargo hold of a steamer docked in Brooklyn on the East River. The boat had been carrying cherries from Michigan, preserved in a chamber kept chilled with dry ice; the boat workers had been bunking in the room where the fruit was stored. Norris’s office found that the men’s blood was “saturated with carbon dioxide and the men had obviously died from asphyxia.” Hastily taken air samples had confirmed that the room was saturated with the gas.

  But as the pathologists emphasized, they’d had to move quickly before the gas was diluted. Carbon dioxide is always found in human blood; and it rises to unusually high levels with other forms of suffocation as well. So carbon-dioxide-rich air samples were essential to determining the method of suffocation. “Exactly the same autopsy picture would have been found if the men had died from being smothered by holding, say, a pillow over their mouths,” one of the medical examiners noted later in his memoir.

  “This brings up a rather interesting possibility for a method of murder that would be extremely difficult to detect,” the doctor, Edward Marten, continued. “I pass this on, for what it is worth, to writers of detective stories.” In his scenario, a sleeping or heavily intoxicated person slumbers in bed. The killer places a bucket, packed with dry ice, on the floor and carefully shuts the windows and door as he leaves. Within a few hours the victim suffocates. When someone opens the door, normal air refills the room, whisking away all trace of the murder weapon: “The trick is that when dry ice evaporates it leaves absolutely no trace behind, so that the investigating detectives would find nothing except a dry and completely empty pail.” Still, Marten considered that a better tip for fiction writers than for real-life killers. The purchase of dry ice was easy to track, the material was tricky to handle, and the gas was rarely and unreliably deadly.

  ON THE other hand, carbon monoxide proved an exceptionally reliable killer.

  Carbon monoxide (CO) is also largely an industrial by-product. When fuel does not burn cleanly away, the process is called incomplete combustion. This less efficient use of fuel makes less oxygen available, creating a situation where, frequently, each atom of carbon bonds with only one atom of oxygen, a connection multiplied millions of times over.

  CO is relatively rare in nature—it forms in the wake of lightning strikes, forest and grass fires, and any event that causes a carbon-rich fuel to burn. Once in the atmosphere, it tends to attach to other free oxygen, converting to carbon dioxide and dispersing. Still, as a 1923 toxicology text noted, it is always present “to a more or less extent wherever man lives and works.”

  The gas was first synthesized by a French chemist, who in 1776 heated zinc oxide with coke (a concentrated form of coal). He’d watched the coke ignite with a beautiful blue-violet flame, a color that scientists would later realize was a signature of carbon monoxide as it burned.

  Carbon monoxide drifted out of lime kilns, brick kilns, charcoal kilns, burning buildings, stoves, grates, braziers, salamanders (broilers), coal-stoked furnaces, gas-water heaters, gas lighting, the smokestacks of trains, and of course, the tailpipes of automobiles. Auto exhaust contained up to 25 percent carbon monoxide, according to tests done in 1926. An even more concentrated source, though, was illuminating gas. This fuel, produced from coal processing, consisted mostly of carbon monoxide and hydrogen. Illuminating gas was preferred for lighting because it produced a particularly bright flame, but it was also used to power stoves, heaters, and even refrigerators. Some of these appliances had registered gas leaks containing more than 40 percent carbon monoxide.

  The risks associated with inhaling high levels of carbon monoxide had been realized quickly, mostly because they made themselves so apparent. Consider the effect of even a small car, a 22-horsepower Model T, left running in a closed garage. An engine that size generated twenty-eight liters of carbon monoxide a minute. Some toxicologists calculated that “this is sufficient to render the atmosphere of a single car garage deadly within five minutes, if the engine is run with the door closed.” The federal government issued a more c
onservative estimate of ten minutes.

  Charles Norris estimated that carbon monoxide killed nearly a thousand residents of New York City every year. Breaking Norris’s numbers down further—say, for the single year 1925—his records showed 618 accidental carbon monoxide deaths, 388 Suicides, and three homicides. The most inventive of the murders involved a man killed by having a gas tube forced into his mouth until the carbon monoxide killed him. The killer then put the dead man into a water-filled bathtub and reported his death as an accidental drowning.

  Unfortunately for the murderer, the man’s lungs contained no water. And when Gettler ran the toxicology tests, evidence of carbon monoxide almost literally spilled out of the blood.

  MOST CARBON MONOXIDE murders involved faking an accident. The standard approach was to blame the death on a leaky heater or poorly closed gas valve, setting it up as just another of the many sad fatalities in the city. Both police and medical examiners acknowledged that these crimes were often difficult to detect, and undoubtedly some murderers were never caught.

  But law enforcement officials had exposed enough of these schemes to warn against homicidal overconfidence.

  One such success, which would be cited by forensic scientists for years following, occurred in the fall of 1923. An out-of-work painter named Harry Freindlich took out a $1,000 life insurance policy on his twenty-eight-year-old wife Leah, smothered her while she lay sleeping, and then attempted to cover it up.

  Freindlich was desperate for money at the time, desperate about everything: he was jobless and unable to pay the rent, much less provide food for his family. The family home was a bare cut above living on the street anyway, a battered tenement on Manhattan’s Lower East Side. The paint was peeling off the walls. The floors were splintered. They’d been patching the appliances together with cardboard, glue, solder, anything. It was one of these cracked appliances that gave him the idea—a gaslight in the bedroom with a troublesome broken fitting that he had soldered back together more than once.

  On an early October morning Freindlich put a pillow over his wife’s face and pressed it tight until she quit breathing. He then tossed the pillow aside and wrenched apart the soldered light. When he heard the hiss of the gas, he hurriedly left the room, closing the door sharply behind him, leaving his dead wife lying beside the baby son she’d brought to bed with her. As the police pieced it together, he then walked out of the apartment, not trying to save the baby or any of the other children sleeping there.

  But that tossed-aside pillow had dropped right on top of the sleeping infant. The little boy abruptly woke and began crying, struggling to get free. The Freindlichs’ oldest child, a ten-year-old boy, heard his baby brother wailing and ran in to see what was wrong. He tried to shake his mother awake. But she didn’t respond, no matter how hard he shook her. Now sobbing, he grabbed the baby and ran to the apartment next door. The neighbor grabbed a candle and hurried to check the darkened apartment. When she saw the dead woman in the bed, she ran to the grocer’s place downstairs to call the police.

  At first it looked like just another accident, maybe a suicide. Leah had been a sweet woman, the neighbors told the police, but worn down, just tired out. But something about the neighbor’s story bothered the beat cops. If there was a lethal amount of illuminating gas in a room, it almost always ignited in the presence of fire, thanks to its explosive mixture of carbon monoxide and hydrogen. Apartments in the city blew up on a semiregular basis when someone unwittingly struck a match in a gas-filled room; Norris’s office kept a file full of pictures showing blackened walls and fragmented furniture.

  If illuminating gas had poisoned Leah Freindlich, it would have built up in the apartment. The room should have flashed to fire when the Good Samaritan ran in with her candle.

  Back at the Bellevue morgue, the pathologist found the scenario equally dubious. The dead woman was sheet pale, all wrong for carbon monoxide poisoning, which tended to flush the skin pink. Before beginning an autopsy, he drew blood samples from her body and asked for a quick analysis from Gettler’s laboratory. The lab results showed that the blood was loaded with carbon dioxide, the typical finding in suffocation, but there was no evidence of carbon monoxide. When the pathologist looked more closely at the body, hidden in the hair at the back of her neck he found a black bruising of fingerprints where someone had pressed fiercely against her skin.

  Freindlich broke into sobs when he was arrested and begged the police to take him to the roof so that he could throw himself off. He couldn’t have killed his wife, he said—no one could have wished her harm. He couldn’t go to jail; what would happen to his children?

  He wanted his old life back.

  CARBON MONOXIDE can be considered as a kind of chemical thug. It suffocates its victims simply by muscling oxygen out of the way.

  In humans and many other animals, oxygen is transported in the bloodstream by the protein hemoglobin. Hemoglobin is classed as a metalloprotein because it contains the metal iron. Its structure, known as a heme, resembles a bright cluster of protein balls around a darker iron core. The iron in hemoglobin stains red blood cells, giving them that deep crimson color even as the protein itself efficiently moves oxygen through the body.

  When a person inhales oxygen, the gas diffuses out of the lungs and into the bloodstream. Then because oxygen molecules are so attracted to iron, they bond to the hemoglobin. The result is called oxyhemoglobin, and in that neat package, the life-sustaining gas is delivered to cells throughout the body. It seems a beautifully designed system. But a chemical vulnerability is built into it, which becomes very apparent with exposure to a poison such as cyanide or carbon monoxide. Both poisons attach to hemoglobin far more effectively than oxygen.

  Thus, these two chemical compounds are life-threatening because they are opportunistic, making deft use of the body’s essential metabolic systems. The attraction between hemoglobin and carbon monoxide is some two hundred times stronger than that between hemoglobin and oxygen. No wonder that CO—as an invading gas—can cram into the blood cells, its tighter grip allowing it to displace the looser oxygen bonds. Oxyhemoglobin disappears; the blood becomes saturated instead with carboxyhemoglobin, crowding oxygen from the blood, locking it out of cells. The result is a chemical suffocation.

  The early symptoms of acute CO poisoning are drowsiness, headaches, dizziness, confusion, and occasional nausea. In the alcohol-hazed 1920 doctors tended to mistake CO poisoning for drunkenness, according to records kept by Norris’s office. Sometimes the physicians just dismissed signs of CO poisoning as the common mental illness seen among the city’s derelicts. That wasn’t necessarily surprising either. Exposure to carbon monoxide can also induce dementia, memory loss, irritability, a staggering loss of coordination, slurred speech, and even a deep feeling of depression.

  Physicians so often got it wrong, at least in 1926, that a CO poisoning was often recognized just at the point when it was too late to save the victim. Or after the patient had been sent to the morgue.

  THERE AT Bellevue, in that sanctum of the dead, it took only a few simple tests to reveal a carbon monoxide death—or the absence of one, in the case of Leah Freindlich.

  As CO absorbs into cells, it turns arterial blood from its normal dark bluish-red into a bright cherry color. The bright blood pinkens the skin at the same time, flushing it a deep rose color, sometimes mottled with red spotting. That was why Leah Freindlich’s pallor alerted the pathologist on duty—he knew it contradicted the scene set by her husband.

  On autopsy, following a carbon monoxide death, the muscle tissues gleam with crimson; so do the organs. The membranes of the throat and lungs are bright red, often covered by a weirdly frothy mucus layer. The brain can appear battered—swollen, dripping with bloody fluid. The cortex can be softened and blood-streaked. Some toxicologists argue that CO ultimately kills by damaging nervous system tissue until the lungs themselves are paralyzed.

  In Alexander Gettler’s laboratory, one of the simplest ways to test for CO
was to extract blood from the corpse, pour some of it into a porcelain dish, and stir in some lye. Lye (a compound of sodium, hydrogen, and oxygen also known as caustic soda) turns normal blood into a dark, gelatinous ooze that, when held to the light, shows murky layers of greenish brown. But blood saturated with carbon monoxide doesn’t darken that way; it stays an eerie, after-death crimson even as it jells, resembling glossy reddish aspic set into the white dish. In every chemical test, though, no matter what combination of materials is mixed into the blood, the dark/bright distinction persists. Blood containing oxyhemoglobin thickens to black, dark brown, or gray. Blood containing carboxyhemoglobin remains, as they say, blood red.

  Chemists weren’t sure exactly what produced that contrast, but they suspected it had something to do with the relentless grip that carbon monoxide exerts on iron components in hemoglobin. The strength of that connection, scientists speculated, might prevent the hemoglobin from breaking down so quickly, thus enabling it to keep staining the blood cells iron-red. But the looser bonds with oxygen might, instead, allow a decomposition of the iron, essentially causing a kind of tarnishing effect, in the way of any oxidized metal, darkening the blood as it did so.

  That explanation was mostly educated guesswork, but of this one thing Gettler and his fellow toxicologists were certain: carbon monoxide did not like to let go of hemoglobin. Left for weeks during time tests, residing in stoppered bottles on the wooden counters of Gettler’s lab, solutions containing carboxyhemoglobin would glow like the crimson hourglass on the abdomen of a black widow spider, like the clear carmine red of warning lights signaling danger to those who got too close.

  WHEN Charles Norris started as medical examiner, he’d decided to track every accidental illuminating gas death that occurred on his watch. During his first month in office—January 1918—there were sixty-five such fatalities, an average of two a day.