WASHINGTON -- U.S. marshals and police arrested a dangerous ex-convict and took his five companions into custody, safely ending a multistate manhunt in the slayings of a wealthy Washington family and their housekeeper.

The fugitive task force tracked Daron Dylon Wint to New York and back before they caught up with him late Thursday night in the parking lot of a suburban motel. Maryland, authorities said. Dozens of officers quietly tailed a car and truck into the nation's capital and then swarmed in so quickly that the group surrendered without a fight.

"We had overwhelming numbers and force," Robert Fernandez, commander of the U.S. Marshal Service's Capital Area Regional Fugitive Task Force, told The Associated Press on Friday. "They completely submitted immediately."

Police have not detailed why Wint -- a welder who once worked for Savvas Savopoulos -- would want to kill the executive, his wife Amy, their 10-year-old son Philip, and their housekeeper Veralicia Figueroa. Three of the four had been stabbed or bludgeoned before their mansion was set on fire on May 14.

The Savopouloses lived in a $4.5 million home in Woodley Park, where mansions are protected by fences and security systems and law enforcement is a constant presence, in part because Vice-President Joe Biden's official residence is nearby.

Wint, 34, was arrested about 11 p.m. Thursday on charges of first-degree murder while armed, D.C. police and the Marshals Service said. He was expected to appear in D.C. Superior Court on Friday Wint is the only person currently charged.

Investigators tracked Wint to the motel in Maryland, where they quickly realized he was probably in one of two vehicles in the parking lot. The car and truck left together, and the team followed as they took a U-turn and a strange route, either getting lost or trying to shake them, Fernandez said.

A police helicopter joined the pursuit from above, and officers eventually got between the two vehicles in northeast Washington. Wint surrendered without a fight and seemed "stoic" as he, two other men and three women were taken into custody, Fernandez said.

"I don't think they knew we were tailing them until the moment we swarmed in on them," said Fernandez.

Fernandez said he noticed a big wad of cash in the truck, but didn't know how much was there. It was not clear whether that money might have been connected to the Savopoulos family. Fernandez said he did not know whether the group was carrying any weapons before local police took them into custody.

Police on Thursday did not rule out the possibility that other people were involved in the slayings, but said no other suspects had been identified.

Wint had worked for American Iron Works, where Savopoulos was the chief executive. The construction-materials supplier has been involved in major projects in downtown Washington.

Messages from the couple in the hours before their slayings confused and frightened their household staff and the slain housekeeper's husband, who said later they felt something was amiss inside the mansion. The executive's Porsche was later found in suburban Maryland, also set on fire.

DNA analysis at a Bureau of Alcohol, Tobacco and Firearms lab linked Wint to the crime, a law enforcement official involved in the investigation told The Associated Press on condition of anonymity for lack of authorization to discuss the investigation publicly.