SAN DIEGO — Eighteen years after a San Diego man was stabbed and killed outside a house party, police and the victim’s family put out a call for justice Thursday.

Salvador Mercado was 25 years old when he was stabbed on Harris Avenue in the South Bay neighborhood of Palm City, just after a party broke up on Nov. 16, 2003.

The person responsible for his murder was never arrested, but detectives continue to search for eyewitnesses or any other information that could close the case. It’s left his family without closure for a tragic loss, but not without hope that someone could finally come forward with answers.

“I believe that we are going to be able to solve this case,” said Mercado’s mother, Maria Najera, in a video produced by San Diego Police Department to raise awareness about the investigation. “And I’m not going to give up.”

Loved ones remember Mercado, who went by “Sal,” as the “light of the family.” He was a father, son and brother. The night of the party, Najera says her son was at the house for dinner and “seemed excited and happy” to head out. She hugged him and kissed him and said goodbye.

Hours later, Sgt. Jesus Sanchez and other SDPD officers were called to the block in Palm City where a large party had just ended and gunshots were reported. Sanchez says he showed up around midnight and saw people running away from the area.

Officers later learned that two people had been stabbed. One of them was Mercado. The 25-year-old was taken to the hospital but pronounced dead a short time later.

“I was told to rush to the hospital because he had been stabbed,” Najera recalled. “When we got there he had already passed away. It was like, you didn’t even have a chance to hope for his life. Because he was gone.”

Many people from the community came out for the young man’s funeral days later. His sister, Angelina Najera, said they were drawn to Mercado because he was the kind of person who was “there to pick you up” if you had a tough day. She says her brother was a mentor through his involvement in local sports.

“He was admired by so many youth in the community because he was there to listen,” Angelina said. “He had so much empathy.”

Who killed Mercado remains a mystery. The host of the house party told authorities that several uninvited people crashed the gathering and that they had just shut things down around the time of the 911 calls, sending partiers out onto Harris Avenue.

“Witnesses saw who we believe to be Sal in a confrontation with another male,” Det. Lori Adams said. “Glass bottles started breaking, a fight ensued, gunshots were heard and people scattered.”

Mercado told someone that he had been stabbed and got a ride to the hospital. A 17-year-old showed up at the medical center a short time later with stab wounds of his own. He told hospital staff he was stabbed on Harris Avenue but police never got a chance to interview him, Adams said. “We would like to speak to him to find out what happened to him and to fully understand what happened that night,” the detective said.

Because it was such a large party, investigators and Mercado’s family remain convinced that more people have the answers they’re looking for, too, even 18 years later.

“If you’re someone that has information and you feel that you want to tell us, but at the same time you are kinda hesitant, you can feel God tugging at your heart. That tug is real,” Mercado’s mother said. “Believe me, when you’ve given up that information, it’s going to give you a lot of peace.”

Anyone with information about the murder — or even basic details on the night of the party — was urged to call the San Diego Police Department’s Homicide Unit at 619-531-2293 or the San Diego County Crime Stoppers anonymous tip line at 888-580-8477.

Crime Stoppers is offering a $1,000 reward to pair with a $9,000 reward from Mercado’s family to anyone with information that leads to an arrest in this case.