Washington - The suspect in the killing of a Washington businessman and three others found in a torched mansion last week was arrested late on Thursday, police said.
The Washington DC Metropolitan Police Department said the suspect, identified as 34-year-old Maryland man Daron Dylon Wint, was arrested in the city's northeast just before midnight local time by a US Marshals Service-led task force.
The bodies of businessman Savvas Savopoulos, his wife, son and housekeeper, were found inside the multi-million dollar house in a neighbourhood near Vice President Joe Biden's official residence after a fire that police called "very suspicious".
Earlier on Thursday, Police Chief Cathy Lanier said Wint was believed to be in Brooklyn. He had worked for Savopoulos' construction materials company, American Iron Works.
Wint has been charged with first-degree murder while armed, authorities said on Wednesday.
Also read: DNA from pizza crust helps police identify US murder suspect
"We do believe that there is a connection between the suspect in this case through the business. Right now it does not appear that this was a random crime," said Lanier, who was flanked by Mayor Muriel Bowser.
Lanier said police have not ruled out that others may be involved in the murders.
Savopoulos, 46, his wife, Amy, 47, their son, Phillip, 10, and housekeeper Veralicia Figueroa, 57, were found dead at the couple's mansion on May 14.
The Savopouloses' Porsche was found torched in Prince George's County, Maryland, outside Washington. The family was active in society in the US capital and in charity work.
Police have said that three of the victims were beaten or stabbed.
The Washington Post reported on Thursday that Wint's DNA had been recovered on the crust of a Domino's pizza that had been delivered to the house. Lanier said she would not discuss evidence.