Last Thursday, Riccardo brought his expertise and fascination with the undead to light when he presented a slide lecture, "Vampires: The Creatures of the Night" at the Forest Park library.

The talk revolves around exploring the mysteries of the vampire in legend, fantasy and fact, including topics ranging from the origins and history of vampire beliefs to reasons for people's varied interests in the night stalkers.

"Vampires, in a way, are an expression of the dark side of human nature," Riccardo said. "They represent mystery, darkness, death and all kinds of forbidden passions. There seems to be an endless fascination about the subject."

Riccardo's own interest in vampirism stems from a childhood drawn to folklore and the supernatural, often manifested in monster movies. As a college student, the Berwyn resident heard a stimulating lecture from Leonard Wolf, author of "A Dream of Dracula," that really brought the caped immortal to life for Riccardo. After watching the 1923 German film, "Nosferatu" and the 1970s movie "Dracula Has Risen from the Grave" starring the magnetic Christopher Lee, Riccardo decided to really sink his teeth into the study of vampires both as cultural curiosity and historical fact.

"Christopher Lee played a very dynamic, powerful Dracula with tremendous strength and vitality," said Riccardo, who has written several books about vampirism, his last published work being "Liquid Dreams of Vampires."

"Vampires started as a terrifying superstition hundreds of years ago in eastern Europe," he said. "Over the centuries, it has evolved into a dark, romantic fantasy. The thought of vampires coming back from the dead, attacking the living in their beds and drinking blood has both fearful and erotic qualities."

According to Riccardo, the legend of vampires developed as early as the late Middle Ages (1400s) throughout eastern European countries like Russia, Poland, Czechoslovakia, Hungary and Greece. Searching for explanations of inexplicable deaths at the time, people would often hallucinate and experience "waking dreams," or sleep paralysis, in which they imagined they were awake but paralyzed as something came to attack them.

In an attempt to assuage their paranoia they would dig up graves of the dead who were "suspected" vampires only to find, much to their horror, signs of the undead, such as enlarged bodies (perceived feeding on the living), as well as blood showing out of the side of the corpses' mouths.

"There is a modern explanation for those signs of the undead," Riccardo said. "When an unembalmed corpse sits in a grave, gases form internally especially methane. As the gases expand, the body expands like a balloon and pushes blood up through the inner organs out through the mouth."

With vampire hysteria prevalent in many towns like Danzig, for example, the legend extended to other parts of Europe, particularly after Bram Stoker's 1897 classic novel, "Dracula." Inspired by the real-life bloodthirsty tyrant Prince Vlad Tepes of Romania, Stoker stoked the fantastic image of vampires, so to speak, by adding new facets to the character including the ability to lie in a box of native soil, turn into a flying bat and having no reflection in a mirror.

Dracula, which means "Son of the Dragon," enjoyed a worldwide phenomenon in the 1930s largely due to the work of the inimitable Bela Lugosi's portrayal of the Count.

"Many of the great actors who played vampires on stage and screen found that there was an amorous attraction from the audience," said Riccardo. "Bela Lugosi received tons of fan letters, often including marriage proposals."

Currently, there are more than 1,000 novels in the English language about vampires, of which 90 percent have been written in the last 35 years.

Naturally, all this vamp-mania begs several questions about the unnatural: Do vampires exist; and if so, has Riccardo met any?

"I don't believe in reanimated corpses that can drink blood," he said. "However, I have come across people who have claimed to have horrific experiences with vampires. There was a young woman from Indiana who told me of her boyfriend who was pale as a corpse with long black hair. She could never detect his heartbeat and he always made it a point to get home before sunrise. At times, she even noticed strange bite marks on her body with no recollection of them. Strangely enough, she said her boyfriend would call her in the middle of the night and he could tell her exactly what she was dreaming about.

"I've talked with a number of people who claim to be vampires but often they are just putting on a façade or affectation," Riccardo said. "Some people, however, claim a real need to drink small amounts of blood from willing donors. It's often a fetish that can have sexual connotations or a fixation with blood often going back to something a person experienced in their youth."

Riccardo hopes people who attend his all-ages friendly slide show just have fun with the fantasy image of the vampire and the vicarious thrill of being frightened. He offers this tongue-in-cheek, or shall we say, once bitten, twice shy sagacious warning to the wise.