A man whose wife and nine-year-old son were killed with three other people in Texas said the attack began after he asked a neighbour to shoot his gun further away from his home.
Wilson Garcia said the attack began 10 to 20 minutes after the man refused his request.
The suspect, 38-year-old Francisco Oropeza, is still at large despite a search involving more than 200 police.
Authorities are offering a reward for any information about his whereabouts but the FBI special agent in charge says investigators have no leads.
People in their rural town north of Houston are used to people firing their weapons to blow off steam, but it was late on Friday and Mr Garcia had a month-old son who was crying.
So, Mr Garcia said, he and two other people went to his neighbour’s house to “respectfully” ask that he shoot further away from their home.
“He told us he was on his property, and he could do what he wanted,” Mr Garcia said after a vigil in Cleveland, Texas, for his nine-year-old son who was killed in the attack that soon followed.
Mr Garcia called the police after Mr Oropeza rejected his request. The man shot some more, and now it sounded louder. Mr Garcia could see the man on his front porch but could not tell what he was doing.
His family continued to called police – five calls in all, Mr Garcia said. Five times the dispatcher assured that help was coming.
And then, 10 to 20 minutes after Mr Garcia had walked back from Mr Oropeza’s house, the man started running towards him, and reloading.
The gunman walked up to the home and began firing. Mr Garcia’s wife, Sonia Argentina Guzman, 25, was at the front door, and the first to die.
The house held 15 people in all, several of them friends who had been there to join Mr Garcia’s wife on a church retreat. The gunman seemed intent on killing everyone, Mr Garcia said.
Also among the dead were Mr Garcia’s son, Daniel Enrique Laso, and two women who died while shielding Mr Garcia’s baby and two-year-old daughter.
Mr Garcia said one of the women had told him to jump out a window “because my children were without a mother and one of their parents had to stay alive to take care of them”.
“I am trying to be strong for my children,” Mr Garcia said, crying. “My daughter sort of understands. It is very difficult when she begins to ask for mama and for her (older) brother.”
Police went door to door on Sunday in hopes of finding any clues that would lead them to the suspect.
They recovered the AR-15-style rifle that they said Mr Oropeza used in the shootings. Authorities were not sure if he was carrying another weapon after others were found in his home, but said he should be considered armed and dangerous.
He probably fled the area on foot. During the early hours of the search, investigators found clothes and a phone while combing an area that includes dense layers of forest, but tracking dogs lost the scent, San Jacinto County sheriff Greg Capers said.
Authorities were able to identify Mr Oropeza by an identity card issued by Mexican authorities to citizens who reside outside the country, as well as doorbell camera footage. He said police have also interviewed the suspect’s wife multiple times.