A Lebanese immigrant’s American dream ended yesterday when he was fatally shot at his Garment District shoe store, police said.

“Every day I saw him working so that he could send some money home to his family in Lebanon,” said a 22-year-old man named Hassan, who declined to give his full name and said he worked in the same building as the victim.

Witnesses identified the victim as 48 year-old Ali Nassir al-Din.

Just after 4 p.m., as he prepared to close his second-floor booth at 15 W. 27th St. for the day, al-Din and his 29-year-old son-in-law were confronted by a third man in the store, according to police. Investigators did not know the reason for the dispute, but said that after a brief argument the man pulled out a gun and began to shoot al-Din and his son-in-law.

Witnesses and others who worked in the building offered conflicting stories.

One witness, Jose Martinez, said he was on the second floor of the building just before the shooting and saw the argument. He said the shooter’s motive was revenge for a bruised ego. He said the gunman wanted to buy something and became enraged when the merchant seemed skeptical that he would make a purchase. “But he had a big wad in his pocket,” Mr. Martinez said.

The dispute seemed strange, Mr. Martinez said, and he quickly left the building. As he was leaving, however, he saw the man who was involved in the argument go down to the street to retrieve friends. The men then went back up to the second-floor store, and shots were fired, Mr. Martinez said.

Another man who worked in the building, who estimated that al-Din would have taken in between $500 and $600 in cash yesterday, suspected that the incident was a robbery gone wrong.

“It was the end of the day and they came to take his money,” Mohamed El-Zaghir said.

Police said nothing was taken from al-Din’s store.

The gunman shot al-Din three times, fatally striking him in the head, neck, and torso, said police. The son-in-law, whom witnesses identified as Samir Said, was grazed in the back by a bullet and taken to St. Vincent’s Hospital, where he was treated and released.

The gunman was described to police as a black man more than six feet tall, wearing black jeans, a black cap, black shoes, and a waist-length black jacket.

Police said they suspect that the 17-floor commercial building, which houses between 50 and 60 booths that sell leather goods, clothing, and sportswear, is a possible outlet for counterfeit goods. The blocks near the crime scene have gained notoriety as a major counterfeit center, bolstered by a late December sweep that saw authorities seize more than $12 million in counterfeit clothing from the area. It was said to be the largest counterfeit trademark sweep in the city’s history.