"I have no idea why it took so long," says St. Louis county medical examiner Mary Case. "To determine whether something tests negative takes two to three weeks, and if it's positive it usually takes four weeks."
Michael Graham, chief medical examiner for the city of St. Louis, is inclined to agree. "These laboratory tests [to detect arsenic] are relatively complicated, but this did take a rather long time," concedes Graham, who performed the autopsy on Mullen.
The 67-year-old Mullen was a well-liked physicist and research scientist at the old McDonnell Aircraft Corporation (now the Boeing Company). He retired in 1999 but remained active as a Boeing consultant. An avid pilot, Mullen co-owned Creve Coeur Airport for nearly twenty years. The father of two grown sons, he'd divorced long ago but had a girlfriend whose daughter was staying at his home at the time of his death.
"He was a really nice guy, a wonderful person, and this was quite a shock," recalls John Cournoyer, one of Mullen's partners at the airport. "There was nothing to indicate there were any problems [at home]."
"This whole thing is bizarre," agrees Al Stix, another airport partner. "I'm still flabbergasted. You just want to know who did it." Stix adds that Mullen was always "very careful about his health," not wanting to lose his pilot's license for medical reasons. "John worked twenty hours a day. He was the most industrious guy I've ever known. He was a very happy, 'up' sort of person."
On the morning of June 29, 2004, Mullen called 911 and said he was feeling very sick. A Chesterfield police officer was dispatched to his home, which overlooks Gumbo Cemetery near the intersection of Long and Wild Horse Creek roads. Paramedics whisked Mullen to St. John's Mercy Medical Center, where investigators were able to interview him. He died later that day.
Police immediately ruled out the possibility of suicide. At a mid-December news conference, Captain Ed Nestor of the Chesterfield Police Department revealed the toxicology findings and declared the case a homicide. Police, he said, looked into Mullen's life-insurance policy and beneficiaries.
Nestor also took the time to single out the work of the officer who had responded to Mullen's 911 call. The officer, Nestor noted, had sensed something about the victim's symptoms that led him to believe the man had been poisoned. (The symptoms of arsenic poisoning include excessive saliva, difficulty swallowing and gastric hemorrhage. As the poison's effects progress, the victim may experience a seizure that usually results in death.) The officer "gathered evidence" at the scene that "turned out to be very helpful. The case certainly would have gone a different way if he had not done it."
Aside from those revelations, however, Nestor was vague -- so vague, in fact, that he declined to name the evidence-gathering cop.
A month later the Chesterfield police captain is still playing it close to the vest. Nestor declines to identify the heroic officer or to comment on any aspect of the case for this story. "I'm a media-friendly guy," he says. "But getting a successful prosecution is what I'm trying to do."
Christopher Long, the St. Louis county forensic toxicologist who performed the tests in the Mullen case, defends the delay in ruling Mullen's death a homicide. "Arsenic cases are different," he maintains. "Sometimes things just take longer."
Long would know: He played a key role in the successful prosecution of a 1995 attempted-murder case involving arsenic. The case, which gained national attention, involved a St. Louis man named Jim Boley who set about to systematically poison his ex-wife, Donna, after secretly upping her life insurance to $600,000. Boley's modus operandi was to put rat poison into the salt shaker his ex used each day and to dose her milk. Long's tests on Donna Boley's hair showed she'd been slowly poisoned over the course of three months or longer. The wife survived; Boley is serving a life sentence.
Long speculates that the massive levels of arsenic found in Mullen's body might have come from an easily obtained, garden-variety ant poison. The toxicologist says his tests showed that Mullen's death was caused by a single massive dose of the substance.
How might Mullen have been poisoned with arsenic? "I can't say why at this point, because that could compromise the police investigation," says chief medical examiner Graham. He will say, however, that in more than 90 percent of all arsenic-related murders, the substance is ingested orally.
Neither the city of St. Louis nor the county keeps records on how often arsenic has been used as a murder weapon. "I've been here since 1981, and I can't think of one," says Graham. In Missouri, according to the Centers for Disease Control, there have been ten murders by poison since 1978. But the federal agency does not track the type of poison used.
Arsenic has been the object of macabre fascination for centuries. Some believe Napoleon Bonaparte's death in 1821 can be traced to arsenic, because small amounts of the substance were found in his hair. (The French ruler's residence was decorated with wallpaper containing Paris green, an arsenic-laced compound used in fabrics that was not recognized as a health hazard until the end of the nineteenth century.) And arsenic was the homicidal poison of choice for murder-mystery writers of yesteryear. In 1944 Cary Grant starred in Frank Capra's Arsenic and Old Lace, the classic comedic tale of two sweet old ladies whose hobby is killing lonely old men and burying them in their cellar.
But murder by arsenic, which seemed almost fashionable in the early nineteenth century, became far less popular when, in the 1830s, British chemist James Marsh developed a sure-fire method for detecting the substance.
"One thing about arsenic," notes Michael Graham. "Once it gets in the body, it stays there forever."