People get grossed out when William Todaro talks about what he does for a living. The bug expert for the county health department can figure out how long a corpse has been rotting by the size of the maggots.
Steve Mellon, Post-GazetteAllegheny County Health Department entomologist William Todaro holds a maggot, actually the larva of a bluebottle fly.
Click photo for larger image.
Somehow, without belittling the deceased, the 58-year-old elegantly speaks on the topic with the enthusiasm of a scientist who has found his true calling: "People don't usually see themselves as a reservoir of flesh and blood that is valuable to other organisms. We build up our flesh at the expense of many other animals, pigs, chickens, fruit. When we die, nature wants to recycle that back into the environment."
Blow flies, he says, are the first to arrive. They start laying eggs on a body within 10 minutes. From that point onward, entomologists can begin tracking a fly's development, or, based on a larva's size, forensically trained entomologists like Mr. Todaro work their way backward.
Homicide investigators turn to him for help cracking cold cases like the one he testified about two weeks ago in Allegheny County Common Pleas Court.
On May 3, 2004, a city building inspector discovered the bullet-riddled body of Kristine M. Switzer in the upstairs bedroom of an abandoned house in Beltzhoover.
Police had no witness, no weapon, no fingerprints, no DNA evidence and no ballistics findings of any use. But by analyzing the "maggot mass" left when the victim's body was removed, Mr. Todaro narrowed the time of the killing down to within a day or two, sometime between April 25 and April 27. April 26 was his best guess.
When a witness came forward four months later, his date corresponded with her recollection: between the 25th and the 27th, probably around April 26.
Lenora L. Maiolo, 33, said she smoked crack at a Day's Inn and then drove around with Augustus Stewart, 48, and Ms. Switzer. She said she saw him fire about seven bullets at the victim, a police informant, before he forced Ms. Maiolo to take a final shot at her.
Based on her testimony and very detailed account from a jailhouse informant, a jury convicted Mr. Stewart Tuesday of first-degree murder. Judge John A. Zottola acquitted Ms. Maiolo Wednesday on all charges related to her role in the killing because she was under duress.
Nature's cleanup crew
A slight, neatly dressed man, Mr. Todaro gleefully endures jabs from his wife and children about his decades-long affection for insects. On the rare occasion he appears in court or more frequently heads elsewhere on official business, he puts on one of a couple of dozen bug neckties they've given him as gifts. In court recently, he wore the ladybug tie, he said, "because this is the season the ladybugs come out."
Like most kids, he admits, he might have tortured a few bugs in the backyard when he was little. But he was not particularly drawn to critters until his tour of duty in 1969, marching through the jungles of Vietnam.
"I was in the Army. I carried a radio. I was a grunt. We'd march through these areas that were napalmed over. They were wiped out. You'd sit down to eat your food and ants and mosquitoes were always there," he said. "When you're sitting in the bottom of a blast crater from a B-52 bomber and the ants come out and they eat lunch with you, it's pretty impressive. It convinced me that these things were worth studying."
Mr. Todaro recalls a conversation with a coroner who was digging through maggots to find the bullets in a dead person's brain. He was baffled that the coroner could be repulsed by the bugs, but not the rotting brain matter. "To me bugs are the cleanup crew. Who else would do that?"
Insects' endurance, their perseverance and adaptability for over 400 million years have made them the most abundant creatures on the planet.
Crawling evidence
Mr. Todaro has worked in the public health system for more than 30 years, heading efforts to control ticks with Lyme disease and mosquitoes that carry West Nile virus. His master's degree work was on flies and mosquitoes and he began helping police departments on crime scenes in the late 1980s. But his craft was honed to a finer degree at a 1995 workshop at Penn State University where he studied how insects respond to a carcass. Scientists there compared dead pigs left in the sun with others in the shade.
"Temperature makes a big difference in how a body decomposes," he said.
The conditions in the Switzer homicide, he said, allowed ample opportunity for flies to lay eggs on the victim's cadaver. It was late April, he said, and fairly cold that year, but flies become active at any temperature above 45 degrees.
The body was in a vacant house with a few broken windows, but dry and free of wind. The victim also had open wounds, allowing easier access for bugs and quickening their growth.
After the coroner removed the body and the police crime unit collected physical evidence, the crime team began recovering fly pupae or cocoons for Mr. Todaro to work with in his Downtown lab. He used a timeline based on which of their three molts they'd been through and calculated how long it took them to become adults. The most developed maggot will be the most useful in finding a precise time of death.
The temperature in a building affects how quickly this happens. So he took temperature samples in the room for 24 hours over a period of four days and compared that data, hour by hour, with the National Weather Service temperatures for the same dates a year prior.
As maggots emerge as adult flies, they crawl as far away as possible from the body to bury and protect themselves from other scavenging carnivores.
Rotting corpses seem disgusting, Mr. Todaro concedes, and he expresses genuine respect for human loss, especially in a case like this. But he waxes philosophical about decomposition: It is the force that makes it possible for life itself to move on, he said.
"People have preconceived ideas about bugs and worms," he said, but small life is what makes room for big life on the planet. "We bury our dead to spare our vision of nature making it look like something hideous. But if [decomposition] didn't happen, the planet would be uninhabitable. It would be hundreds of miles thick with dead trees and dead bodies that never rotted."
