The brains typically come by Federal Express. They arrive a couple of times a month at the laboratory of Dr. Hannes Vogel, director of neuropathology at Stanford University Medical Center. He prefers to receive them whole, fixed in formalin, along with their coverings and spinal cords.

One of the next brains to arrive, expected early next week, will be that of Stephen Paddock, who killed 58 concertgoers in Las Vegas earlier this month in a rampage without any clear motive. While law enforcement officials attempt to understand the mass shooting by gathering evidence and interviewing those who crossed the gunman’s path, Vogel is preparing to look for clues in the remains of Paddock’s brain. In a series of interviews, the first he has given on the case, he spoke about the work he plans to do.

Earlier, the office of the Clark County coroner had announced that an autopsy on Paddock had been completed and that tissues from his skull would be sent to Stanford to search for a potential brain disorder.

“Don’t spare any expense,” Vogel said he was told by a pathologist in the coroner’s office.

“The magnitude of this tragedy has so many people wondering how it could have evolved,” Vogel said.

That includes whether any one of more than a half-dozen neurological diseases proposed to the coroner’s office might have played a role. Even though the chances of finding answers in the brain tissue to the mystery of Paddock’s act are slim, Vogel said, “all these speculations out there will be put to rest, I think.”

Examinations of the brains of individual mass killers have been performed in the past, but experts said they were not aware of any compilation of the findings.

Vogel, one of the relatively few academic neuropathologists to focus on forensics, said he planned to look for and photograph any gross abnormalities, such as a tumor or malformation, that could be felt or seen by the eye alone.

Then he will focus on interior structures. Paddock’s brain has already undergone an initial assessment, but Vogel will probably dissect it further, cutting vertically from the top with a large knife oriented as if from ear to ear. He will take samples of the tissue, and colleagues will create paper-thin slices, mount them onto slides and treat them with stains that highlight potential abnormalities of individual cells.

Vogel said he was briefed Wednesday about the condition of the shooter’s brain, including damage caused by an apparently self-inflicted bullet wound to his head. While the injury may compromise the overall assessment of the brain, he said, “I think for a lot of things people are speculating about, it’s still quite usable, pending viewing it.”

Still, he and five other experts in his field sought to dampen public expectations.

“It’s a tricky, tricky business,” said Dr. Jan E. Leestma, the author of the textbook Forensic Neuropathology and a consultant who, a decade ago, offered testimony opposing that of Vogel in a murder case. “The correlation of what might be structurally there to behavior is very difficult. Often it raises more questions than it answers.”

Leestma pointed to the case of another mass murderer, Richard Speck, who was found guilty in the killings of eight student nurses in Chicago in 1966 and later died in prison. Leestma detected a possible abnormality in the man’s hippocampus, a structure involved in memory and the brain’s emotional pathways. However, when he sent the hippocampus to a specialist for further analysis, the specimen was lost in transit, he said.

“Nobody knows what happened to this guy’s brain,” he said.

Another problematic case, which Leestma wrote about in his book, also took place in 1966. Charles Whitman, a student in his mid-20s, shot 45 people from the top of a building at the University of Texas, Austin. A pathologist who performed an autopsy on Whitman said he found a mass in the back of the brain, but the doctor did not document his findings appropriately. An expert panel later reviewed the remaining brain tissue but could not establish whether a block of tissue containing the mass — a tumor — had come from Whitman’s brain or from someone else’s. Even if the tumor was Whitman’s, the role it might have played in the violent events was never determined.

“It’s one of these twisty turning things that becomes more twisted as it goes along,” Leestma said. “It’s an open question. Did the guy really have a brain tumor? What did it do to him?”

Vogel had similar views on Whitman’s widely cited case. The supposed brain tumor “was a very handy excuse for the fact that he went out and shot people,” Vogel said. “I don’t think I ever heard in my own experience of someone on a homicidal rampage because they had a brain tumor.”

Still, the brains that Las Vegas sends to Vogel for review — 129 in the past five years — are “enriched for very puzzling cases in life,” he said. “It’s like that old show ‘Six Feet Under,’” he said, referring to the HBO series about a family-run funeral home in which each episode began with a death.

A minority of Vogel’s cases involve a possible homicide. One concerned accusations that a mother had caused her child’s death through mistreatment leading to brain injury. Vogel’s examination found a different explanation: a serious malformation in the child’s brain that had been mischaracterized based on imaging studies.

“Each one is a sad tale of life and death,” Vogel said.

In the case of the Las Vegas gunman, who was 64, there has been speculation focused on a disease process known as fronto-temporal lobar degeneration. It affects areas of the brain that are vital for “executive functions” like decision-making and social interaction. The disease often strikes in a patient’s 50s or 60s and can cause marked personality changes; it is sometimes hereditary.

“These people are notoriously prone to errors in judgment and unrestrained behavior,” Vogel said. But in Paddock’s case, “people will say in the same breath that this guy was so meticulous in planning and so forth, that that would seem unlikely.”

Still, he said that in his examination of the brain, “that would probably be the area I wouldn’t want to leave any stone unturned.”

Stanford typically has a weekly session where brains are cut and studied in a side room of the hospital morgue, with a group in attendance that includes senior doctors and trainees. But Vogel said he would probably analyze Paddock’s brain alone, because of the high profile of the case. The results will be sent directly to the coroner’s office, he said, and all the materials returned.

Vogel said the price of a basic brain examination, including microscopic views of eight to ten sections, runs about $500, including both the hospital’s and the doctor’s fees. Using special stains on the tissue can increase the price.

He said he would look for signs of all the standard detectable neurological entities, including strokes, blood vessel diseases, tumors, certain types of epilepsy, multiple sclerosis, degenerative disorders, physical trauma and infections. Most psychiatric illnesses, however, are not currently discernible by this type of examination.

“I think everybody is pretty doubtful that we’re going to come up with something,” Vogel said. “The possibilities, neuropathologically, for explaining this kind of behavior are very few.”

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