Three people were shot late Monday night at Wheatley Courts in the 1800 block of Hays on San Antonio's East Side.
San Antonio police said two groups of people got into an argument, then one man opened fire around 10:40 p.m.
When police arrived, all of the victims had left the scene.
K.K. Richardson heard the gunshots right outside his door, and said when he looked outside, there was someone lying on the ground.
"I told them I was going to call 911, and I went back inside the house to grab my phone, and I came back outside, and he was gone," he said.
"Later on, they responded about 20 minutes later to another address where there was two gunshot victims. Through the investigation, the officers were able to determine that these incidents were related," said San Antonio police Officer Roger Zuniga.
One victim was treated by EMS at a home in the 300 block of Gabriel Street for a gunshot wound to the ankle. Another victim was taken to the hospital after suffering a gunshot wound to the calf.
While police were investigating the shooting at the home on Gabriel Street, they received word of another victim who showed up in the emergency room at Downtown Baptist. He had been shot in the knee, police said.
Zuniga said it is not uncommon for victims to leave the scene.
"A lot of times, they're trying to get away from a situation that's violent and dangerous, and so they'll flee, and then they'll try to get help after that. Which, it appears, that's what happened."
Police said the shooter is related to one of the victims, and they are working on tracking him down.