An investigator with the Bureau of Alcohol, Tobacco, Firearms and Explosives leaves the D.C. home where four people were found dead, including Savvas Savopoulos, Amy Savopoulos and their housekeeper, Veralicia Figueroa. (AP, Tony Powell/Washington Life Magazine, Courtesy of Veralicia Figueroa's family)

Nine months after the bodies of three family members and their housekeeper were found in a stately, upper Northwest Washington home that had been set on fire, federal prosecutors Wednesday indicted their sole suspect on 20 counts including first-degree murder, burglary and kidnapping.

Daron Wint, 35, of Lanham, Md., was charged with multiple counts of first-degree murder in the slayings of businessman Savvas Savopoulos, 46, his wife, Amy, 47, their son, Philip, 10, and housekeeper Veralicia Figueroa, 57. Police discovered the bodies May 14 after firefighters were called to the home to investigate a fire.

Wint, who once worked at a Savopoulos family company, is the only suspect arrested in the case. But police and prosecutors have said in court papers that they think others may have been involved in the slayings. Two months after the bodies were discovered, police said they were continuing to pore over “hundreds” of pieces of evidence.

A D.C. police spokesman said Wednesday that the investigation into the killings was continuing.

Federal prosecutors indicted 35-year-old Daron Wint on 20 felony counts on Feb. 17, in the 2015 killings of the Savopoulos family and their housekeeper. (WUSA9)

Police have said that the four victims were held captive overnight and that the attacker or attackers fled with $40,000 in ransom money delivered to the home, in the 3200 block of Woodland Drive NW.

The slayings ripped through the quiet D.C. neighborhood near Vice President Biden’s residence.

Wint is charged with more than one count of murder in connection with each victim, crimes that include murder during a kidnapping and murder during a burglary. Wint also was charged with first-degree burglary, extortion, arson and first-degree theft.

In addition, the D.C. Superior Court grand jury found “aggravating circumstances” and deemed that the alleged murders were “especially heinous, atrocious or cruel” according to the indictment. If found guilty during trial, Wint could face a maximum of life in prison without early release on each of 12 murder charges. The District does not have a death penalty.

Prosecutors have alleged that Wint entered the house May 13, and that he forced Amy Savopoulos to call a nearby Domino’s Pizza and have two pizzas delivered to the house that evening. Authorities have said Amy Savopoulos paid with a credit card and instructed the driver to leave the pizzas outside the house. When the driver arrived, the detective said, the house was dark, except for the porch light.

Authorities have said they identified Wint as a suspect after his DNA was found on pizza crust at the home.

Detectives also told a D.C. Superior Court judge in a previous hearing that Wint’s DNA was found on a neon-green construction vest that was inside a blue Porsche taken from the Savopoulos home. The car was found burned in New Carrollton, Md.

According to the indictment, the adults were stabbed and beaten with a baseball bat, and Philip was stabbed and burned.

Wint was arrested days after the slayings and remains in the D.C. jail awaiting trial.

Wint once worked for a Savopoulos family business, American Iron Works. Authorities said they found $10,000 in the truck that Wint was in when he was arrested. Court documents say authorities found money orders exceeding $10,000 and a large stack of $100 bills, the same denomination delivered to Savopoulos in the $40,000 delivery.

A hearing is scheduled Friday in D.C. Superior Court.