WASHINGTON -- A former Marine and ex-convict accused in the slayings of a wealthy executive and three other people had worked for the businessman's construction company and is believed to be on the run in New York, authorities said.

Police searched Thursday for Daron Dylon Wint, 34, who may have friends and family in the Brooklyn area of New York and was seen there Wednesday night, authorities said. Wint is being sought on a first-degree murder charge.

"Right now, you have just about every law enforcement officer across the country that is aware of his open warrant and are looking for him. Even his family has made pleas for him to turn himself in," Washington police Chief Cathy Lanier said.

Wint is suspected in the killings of 46-year-old Savvas Savopoulos; his 47-year-old wife, Amy; their son, Philip; and housekeeper Veralicia Figueroa. Firefighters found their bodies when they responded to a fire at the family's house May 14. Authorities believe the fire was intentionally set.

Investigators believe Wint, a certified welder, worked for Savopoulos' company American Iron Works in the past. Savopoulos was the chief executive of American Iron Works, a construction-materials supplier based in nearby Hyattsville, Maryland, that has been involved in major projects in downtown Washington.

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

"For residents of the district who are rightfully scared and want answers as to why and how this family may have been involved, we want to give you as many answers as we can," Lanier said. "What we can tell you right now is that we do believe there is a connection between the suspect in this case through the business. So right now it does not appear that this was a random crime."

Investigators used DNA analysis conducted at a Bureau of Alcohol, Tobacco and Firearms lab to identify Wint, according to a law enforcement official who spoke on condition of anonymity because the official was not authorized to discuss the investigation publicly.

New York Police Commissioner William Bratton said he received a call from the D.C. police chief Thursday, saying the suspect may be in south Brooklyn. Officers are circulating a photo of Wint.

"We have a very active investigation here in New York at this time, assisting our colleagues in the Marshal Service and the Washington, D.C. Metropolitan police," Bratton said.

Wint was convicted of second-degree assault in Maryland in 2009 and sentenced to 30 days in jail, online court records showed. He also pleaded guilty in 2010 to malicious destruction of property, and a burglary charge in that case was dropped.

Wint was born and raised in Guyana and moved to the United States in 2000, when he was almost 20 years old, according to court records filed in Maryland. He joined the Marine Corps that same year and received an honourable discharge for medical reasons, the records show. Following his discharge, he worked as a certified welder, the records show.

Savopoulos moonlighted as a martial-arts instructor and had planned to open a martial arts studio in northern Virginia.