DC Mansion Fire: How Police Used DNA to Connect Suspect to Pizza Crust

— -- A DNA sample left on an uneaten pizza crust led investigators to the identification of the suspect in the quadruple murder inside a Washington, D.C., mansion last week, authorities said.

Charles Smith, the Bureau of Alcohol, Tobacco and Firearms special agent in charge for this case, told ABC News that the ATF’s specialized lab determined the DNA match that broke the case.

Smith said agents “started working right about the time the fire happened and they worked through the weekend exclusively on the evidence taken from that location, and because of that, the evidence that we got, we were able to get a hit on a DNA match.”

Daron Dylan Wint was named by Metropolitan Police as the suspect in the murders after they allegedly discovered his DNA at the scene, sources confirm to ABC.

Authorities have not ruled out more than one person being involved in the crime.

"I can tell you that the investigation is still ongoing, we haven't ruled out that it is one person or maybe several people," Smith said. "We haven't ruled out there was or was not participation from other people involved here.”

Investigators have not said specifically how they connected the 34-year-old to the DNA, but many states including Maryland keep DNA records of prior arrestees, especially those charged with felony offenses.

Wint has previously been charged with second-degree assault four times and one fourth-degree sexual offense, all in Prince George’s County, Maryland. Three of the assault charges and the sexual offense charge were dropped but he was found guilty of second-degree assault in March 2009.

Another guilty charge came in February 2010 when he pleaded guilty to malicious destruction of property over $500 after an incident when he threatened to kill a woman and her 2-year-old daughter, broke into her home, stole her television and smashed her car. He spent 32 days in jail and two years probation as part of his sentence.

“He's very hostile. He's arrogant. He's doesn't listen. You try to tell him and guide him the right way, but he thinks he knows the law,” one of Wint’s relatives told ABC News.

The relative, who does not want to publicly disclose her name, said that he was due in court on May 14, the same day that the Savopoulus family’s home was found on fire and the bodies of four victims -- those of Savvas Savopoulus, his wife Amy, their son Phillip and housekeeper Veralicia Figueroa -- were found dead inside.

The pizza crust was the main source of the DNA identification, sources close to the investigation told ABC News. The pizza came from a Domino's delivery made to the home at roughly 9 p.m. Wednesday night, the night before the fire.

A source with knowledge of the transaction said that the two pizzas ordered to the home were paid for with a credit card and the person who called Domino's to make the order requested that they put a $5 tip on the bill. The source was not able to confirm the identity of the caller.

The police said that another avenue of possible evidence would be a Porsche that belonged to Savvas Savopoulus that was found abandoned and burned in a church parking lot 13 miles from the home.

ABC News' Katherine Faulders and Jack Date contributed to this report.