Timothy J. Stenovec Detectives have continued working at the crime scene along East Seventh Street through the afternoon.

The authorities this afternoon identified the victim of a fatal stabbing on East Seventh Street even as detectives were still trying to determine a motive for the crime.

Police said that the victim, Christopher Jusko, was stabbed once in the neck about 5:30 this morning inside an apartment at 272 East Seventh Street. Mr. Jusko, who was 21, was pronounced dead at the scene.

Investigators said that one man was in custody in connection with the stabbing although the authorities did not release his name. Residents along East Seventh Street said that both Mr. Jusko and the man who is in custody had been acquaintances.

John Bonilla, a resident of the building where the stabbing occurred, was leaving his third-floor apartment at 6:30 for a walk, when he noticed a trail of blood coming from the second floor. He followed it down the stairs, and outside the entrance to his building he came across a body covered with blood.

“It was just like bang-bang-bang, you’re walking down the stairs and all of a sudden you see that blood,” said Mr. Bonilla. “And then I came out and found that,” he said, pointing toward the body, which was covered with a white sheet. “It was a bad scene to wake up to.”

Mr. Bonilla, 59, who is a retired post office worker and has lived in that apartment for seven years, said that he did not recognize the victim and does not think he was a resident of his building. “You know the people that you live around,” he said. He described his neighbors as “good, hard-working people.”

Apart from occasional loud music coming from the second floor, Mr. Bonilla said that there had been no problems in the tenement, which is a six-floor walkup with 24 units.

Clyde Ramos, 22, another resident along East Seventh Street, knew both the victim and the man who is in the custody of the police. “We’ve all gotten into fights,” Mr. Ramos said. “We’re a bunch of boys growing up together. But this is a wake up call. This is a young death and it’s good for nothing.”

Claire Glass and Clint Rainey contributed information to this report.