DNA on pizza crust leads to murder suspect

Domino’s had delivered around time four killed

• The critical clue that led District of Columbia police searching for a suspect connected to the deaths of four people at a home in an upscale Washington neighbourhood was a leftover pizza crust.

Three law enforcement officials with knowledge of the investigation said Daron Dylon Wint, 34, was a match for DNA evidence left on the crust of a Domino’s pizza delivered to the home on May 13.

They believe Savvas Savopoulos, 46; Amy Savopoulos, 47; their 10-year-old son, Philip; and housekeeper Veralicia Figueroa, 57, were held captive overnight in the multimilliondollar home, then killed before the house was set afire the following day.

Despite the fact the home had been burned, D.C. Police Chief Cathy Lanier said investigators had been able to collect quite a lot of evidence from the scene, including a video and DNA samples.

Hunger and perhaps an oversight may have caused the suspect to leave a critical clue in this growing murder mystery that has captivated and terrified Washington.

“It’s not unusual for criminals to leave their evidence behind,” said Lawrence Kobilinsky, an expert on DNA technology. “In fact, it’s quite common.”

During home break-ins, criminals are often known to do something very simple: eat.

“They usually do strange things,” noted Kobilinsky, chairman of the forensic sciences department at the City University of New York.

“They’ll eat food from the refrigerator and thereby leave their DNA. Or they’ ll leave their cigarette butts and leave their saliva. They just seem to go out of their way to leave their calling card behind.”

Four years ago, police arrested a man they suspected to be the elusive East Coast rapist after collecting one of his discarded cigarette butts and making a DNA match. Aaron Thomas was eventually sentenced to life in prison.

From a forensic standpoint, finding a partially eaten piece of pizza — or a spent cigarette butt — is like stumbling upon a pot of gold. And in the case of the quadruple homicide, the task of determining when the DNA had been left was made easier because police quickly learned a Domino’s driver had delivered the pizza to the home around the time the crime was being committed.

A law enforcement source noted the suspect appeared to have eaten the pizza wearing gloves, not realizing his saliva was being left behind.

“In the case of crust, you probably have bite marks,” Kobilinsky said. “You’re talking about saliva, and saliva has a lot of DNA.”

Tests on the pizza crust were conducted by the federal Bureau of Alcohol, Tobacco, Firearms and Explosives. The DNA profile from the crust could be matched to convicts or suspects in other crimes from either local, state or federal databases.

“The reason why this works for law enforcement is that most of these guys are recidivists,” Kobilinsky said. “If they were not in the database, (investigators) wouldn’t be able to identify them.”

With a potential match in the database, investigators would need to test an actual DNA sample taken from the suspect and compare it to the one taken from the crime scene.

Human error is, of course, possible. But in general, Kobilinsky says, DNA evidence — especially from a high-quality saliva sample one might get from a bitten pizza crust — is pretty accurate.

“It’s almost redundant to say that DNA remains the gold standard of forensics,” Kobilinsky said. “And compared to any other type of analysis, DNA is at the highest level. It’s in an exalted status.”

You’re talking about saliva, and saliva has a lot of DNA