The family, clad in black, stood at the curb of the road sobbing. A middle-aged mother slapped her cheeks, letting out piercing wails. The father, a frail man who worked as a doorman at a clinic in central Tehran, wept quietly with his head bowed.

Minutes before, an ambulance had arrived from Tehran's morgue carrying the body of their only son, 19-year-old Kaveh Alipour.

On Saturday, amid the most violent clashes between security forces and protesters, Mr. Alipour was shot in the head as he stood at an intersection in downtown Tehran. He was returning from acting class and a week shy of becoming a groom, his family said.

The details of his death remain unclear. He had been alone. Neighbors and relatives think that he got trapped in the crossfire. He wasn't politically active and hadn't taken part in the turmoil that has rocked Iran for over a week, they said.

"He was a very polite, shy young man," said Mohamad, a neighbor who has known him since childhood.

When Mr. Alipour didn't return home that night, his parents began to worry. All day, they had heard gunshots ringing in the distance. His father, Yousef, first called his fiancée and friends. No one had heard from him.

At the crack of dawn, his father began searching at police stations, then hospitals and then the morgue.

Upon learning of his son's death, the elder Mr. Alipour was told the family had to pay an equivalent of $3,000 as a "bullet fee"—a fee for the bullet used by security forces—before taking the body back, relatives said.

Mr. Alipour told officials that his entire possessions wouldn't amount to $3,000, arguing they should waive the fee because he is a veteran of the Iran-Iraq war. According to relatives, morgue officials finally agreed, but demanded that the family do no funeral or burial in Tehran. Kaveh Alipour's body was quietly transported to the city of Rasht, where there is family.

Everyone in the neighborhood knows the Alipour family. In addition to their slain son, they have two daughters. Shopkeepers and businesses pasted a photocopied picture of Mr. Alipour on their walls and windows. In the picture, the young man is shown wearing a dark suit with gray stripes. His black hair is combed neatly to a side and he has a half-smile.

"He was so full of life. He had so many dreams," said Arsalan, a taxi driver who has known the family for 10 years. "What did he die for?"