A Maggot for the Prosecution

Researchers like Meek wish that a forensic entomologist could be part of every crime-scene investigation, but with so few experts in the country, the next-best approach is for homicide investigators to be trained to do the necessary fieldwork. Some police departments are beginning to send their officers to "police entomology" courses held at universities around the country. Among them is the annual spring workshop directed by K. C. Kim at Penn State. This year found Kim, Haskell, and grad student David Skipper leading a line of detectives, pathologists, and coroners through the woods behind the Penn State campus.

"In the seventies or eighties, my superiors would have laughed at this," said Pennsylvania state trooper Jim Shubzda as he traipsed through the forest. "Maggots were just something we pushed aside to look at other Stuff."

As the group approached a forested area, the breeze grew perfumed with a sweet, skunklike smell. The more jaded in the group grinned at the familiar scent. "We've got some stinkers," someone cracked. Pushing aside branches, the group followed a deer trail leading to Joe Pig 1, 2, and 3. Spaced about 100 feet from each other, the victims lay in three different stages of maggot-infested decay. (The pigs had been killed by injection before being brought to the forest.)

Pig 1 was especially ripe that morning. The group's arrival dispersed a thick cloud of chunky black flies. Not so easily disturbed was a swarm of plump maggots churning inside an open wound on its flank. Masses of smaller maggots packed themselves into the pig's mouth and nostrils. Dusty patches of empty egg cases still clung to the wiry hairs around the cavities.

"Listen," whispered Skipper. Bending close to the open flank wound, students could catch the crackling of feeding maggots. Then a cascade of maggots tumbled out, pouring onto the ground. "Periodically they have to come up for air to cool off," Skipper explained. "A big maggot mass can generate a lot of heat."

The class broke into three groups, each assigned to a pig whose time of death they had to determine based on the insect evidence. "I want a nice sample of maggots from each wound and orifice," Skipper told his students. "Then get me at least one of everything else you can find." He supplied everyone with alcohol vials for preserved specimens and "maggot motels" (icecream cups with beef liver) for rearing live ones.

"All these things we're teaching you are to keep us from getting beat up in court," added Haskell. He launched into a diatribe on botched collections. "Once all we had were some squished maggots on a bloody blouse. I mean, for Christ's sake, they'd been stuffed in a paper bag and left in an evidence locker for over a year!"

Haskell reached for a long-handled butterfly net and then waited for a half-dozen blowflies to settle on Joe Pig 1's rump. He skimmed the net gracefully over the carcass and then gave the net a twist to trap several flies. After transferring the specimens into a vial, he handed the net to a pathologist to catch some flies of her own. She whacked the pig on the rump and came away empty.