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.

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 mass killers have been performed in the past, but no common findings have emerged.

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.

New York Times

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.’’

In the case of the Las Vegas gunman, who was 64, there has been speculation focused on a disease process known as frontotemporal 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.’’