"I know I am done," Mingdong Chen said to relatives who discovered him, according to a criminal complaint.
Chen appeared briefly in Brooklyn Criminal Court in oversized blue sweats, his hair disheveled. He was also charged with assaulting a police officer while being questioned at a precinct after the grisly killings Saturday evening.
Chen did not speak and did not enter a plea. His attorney, Danielle Eaddy, said her client had been injured while in police custody and appeared to have two bruises on his forehead. She did not immediately request a psychiatric hearing.
Chen was held without bail. His next court date was set for Friday, where a grand jury was expected to determine whether to indict him in the deaths of 37-year-old Qiao Zhen Li and her children, Linda, 9; Amy, 7; Kevin, 5; and 18-month-old William, all with the last name Zhuo.
Police said Chen stabbed and slashed the victims in their necks and torsos. The family was found in various rooms in their apartment on the first floor of a two-story brick house. Some were hospitalized and pronounced dead; others died at the scene.
"It's a scene you'll never forget," said Chief of Department Philip Banks III.
Chen had been staying with the family for about a week. He was a transient and illegally in the United States, Assistant District Attorney Mark Hale said. An immigration hold was also placed on him.
Police said Chen apparently was envious of fellow immigrants' successes in America.
"He made a very soft comment that since he came to this country, everybody seems to be doing better than him," Banks said Sunday.
Chen was unemployed after being fired from a string of restaurant jobs he held for just a few weeks at a time, according to neighbors and relatives in the working-class Brooklyn neighborhood dominated by a large community of immigrants from China.
The children's father, Chen's cousin, was not home late Saturday evening; he was working at a Long Island restaurant, one neighbor said. The mother tried to call him because she was alarmed about Chen's behavior earlier in the evening, police said.
Neighbors and relatives said the father was distraught over the deaths.