US police say they have arrested a man accused of murdering members of a wealthy family and their housekeeper before setting their house alight in Washington, DC last week.

Daron Dylon Wint, 34, was arrested in northeast Washington late Thursday night, US Marshals Service spokesman David Neumann said on Friday.

Wint is charged with first-degree murder while armed, said Neumann.

He is accused of killing Savvas Savopoulos, 46; Amy Savopoulos, 47; their 10-year-old son, Philip; and housekeeper Veralicia Figueroa, 57, in Washington, DC in May 14.

Police believe the victims were stabbed and doused with gasoline before the house was set on fire.

The incident happened in Woodley Park, a neighborhood that is under constant watch of federal law enforcement officers, in part because Vice President Joe Biden's official residence is nearby.

Nelitza Gutierrez, a housekeeper who worked for the family for 20 years, said she believed the victims were held captive for nearly a day before they were killed.

Gutierrez said she got an unusual voice mail from Savopoulos and a text message sent from the phone of his wife, telling her not to come to the house. She called and texted back, but received no response.

Savvas Savopoulos and his wife were found dead on May 14.

Authorities said Wint’s DNA was recognized on a discarded crust from a pizza that was delivered to the house on the day the incident occurred, according to The Washington Post.

Five other people, including Wint’s brother, were also arrested and taken into custody without incident.

Police, however, have not said why the suspect would want to murder the family.

SB/HRJ