Charles A. Radin of the Globe staff contributed to this report.

Police were searching for suspects last night in connection with an early morning shooting at a South Boston tire shop that left a 25- year-old Dorchester man dead and another man injured.

The victim, Luis Carvalho, was gunned down about 12:30 a.m. yesterday by an unidentified assailant and pronounced dead at Boston Medical Center 45 minutes later, police said. The second victim, identified only as a 24-year-old black male, was shot at least twice and taken to Boston Medical Center. His wounds were not believed to be life-threatening, police said.

The homicide, Boston's fourth of the year, occurred against the backdrop of a string of retaliatory murders that have plagued the city's burgeoning Cape Verdean community, dating back at least to the 1995 stabbing death of Bobby Mendes. Carvalho and Mendes were cousins, and Mendes's mother was among the dozens of family members who came to the Carvalho home yesterday.

The shooting also took place in the midst of a marked drop in gun violence, both citywide and among Cape Verdean youths, who have been the main target of the "Boston Strategy" against youth violence.

As a result, police, community leaders, and clergy are likely to question whether the inroads they seemed to have made are merely superficial.

"Are we back to square one?" asked the Rev. Filipe Teixeira, minister of St. Martin De Porres Church in Dorchester and a Cape Verdean community activist. He was standing in front of the Berry Street triple-decker where Carvalho lived. Carvalho's mother, Rosa, could be heard wailing in the family's second-floor apartment.

"This is a tremendous loss for the community," Teixeira said. "The people have been begging for us to stop the violence, and we have worked nonstop to help them. This is a terrible setback."

A year ago, police rounded up 19 Cape Verdeans - all purportedly tied to the spate of gun violence - and handed them over to the federal Immigration and Naturalization Service for deportation.

This week, community leaders angrily protested the arrest of Amando Baptiste, 22, who had become active in combatting youth violence among Cape Verdeans. He was detained after someone tipped off immigration officials that he has a criminal record, marking him for deportation.

Teixeira, who worked closely with Baptiste in the community, said he came to console the Carvalhos - and to ask the family to help end the cycle of violence.

"We need a way to stop the pain," he said.

Family members were struggling to cope with Carvalho's death.

"I don't believe it," said a teary-eyed Adilson Carvalho, Luis's uncle, shaking his head. "I don't believe it."

Neither could Bobby Allen, who arrived for work yesterday morning at the 24-hour Boston Tire Service, near the South Bay Shopping Center, to find his co-workers unusually enthusiastic to get home.

"When I got here, they just wanted to get the hell out of here," Allen said. "My guys are OK. They said that two guys were in here getting their car worked on, and another guy showed up and just started shooting. That's never happened before," he said.