(CNN) An investigation that began after flames devoured a $4.5 million mansion led to a grand jury indictment Wednesday in the killings of three people from a prominent Washington family and their housekeeper.

Darron Dellon Dennis Wint is the lone named suspect in the Washington quadruple homicide case.

He's set to be arraigned on Friday.

Investigators found the remains of Savvas, Amy and Philip Savopoulos and housekeeper Veralicia Fernandez last May inside the charred home, which is located in northwest Washington near a number of embassies and Vice President Joe Biden's residence.

Police arrested Wint the next week after his DNA was allegedly found on a pizza crust at the scene , according to a source with knowledge of the investigation.

Forensic analysis also matched traces of blood on Wint's shoe to at least one of the murder victims, two law enforcement officials said.

The indictment returned by the grand jury does not detail the evidence against the suspect, who is also known as Daron Dylon Wint.

It says Savvas and Amy Savopoulos and their housekeeper were beaten with a baseball bat and stabbed.

An indictment says Savvas and Amy Savopoulos were stabbed and beaten to death.

Philip, their 10-year-old son, was stabbed and burned, according to the indictment.

Wint is also accused of setting fire to the Savopoulos family's home.

While authorities haven't ruled out others being involved, Wint is the only suspect they've identified in the killings.