CLEVELAND, Texas — The sound of gunfire — whether from hunting, or target practice, or celebration — is common in much of rural America. Perhaps nowhere is this more true than in Texas, where the occasional volley rarely raises alarm.
So when someone from an immigrant family from Honduras called 911 on Friday night to report that their next-door neighbor was shooting from his small property in San Jacinto County, the police did not to rush to the scene. Officers did not arrive until after the neighbor had stormed into the family’s house and killed five people, including a 9-year-old boy and a 16-year-old girl, with his AR-15-style rifle.
On Tuesday, state and federal law enforcement agencies were on the fourth day of an extensive manhunt for the neighbor, Francisco Oropesa, 38, and still struggling to understand why his aimless shooting, of the sort common in that part of Texas, had turned into a massacre.
More than 250 officers from a dozen agencies were working to find Mr. Oropesa, a Mexican immigrant who had been deported four times before. Law enforcement officials feared that he could be heading to Mexico, or may have already arrived there.
“Francisco Oropesa could be anywhere,” the Houston office of the F.B.I. said in a statement on Tuesday, adding that officers were working around “the state, country and across the border.”
The lack of a rapid police response to the family’s initial call for help, shortly after 11:30 p.m., raised questions about how to handle reports of gunfire in Texas, where the ownership of weapons has become less regulated. Some rural officers may also have difficulty distinguishing between noise complaints related to legal and harmless shooting activity and those that represent potential threats.
Texas law affords broad leeway to people firing weapons in rural areas, preventing regulation by local counties on properties larger than 10 acres. Counties may explicitly bar shooting on smaller lots in subdivisions, but many have opted not to do so, relying instead on more general rules preventing recklessness or firing over property lines. Officials in San Jacinto County said that was the law there, and it would have made shooting in the yard, of the kind the family had reported, illegal.
“I get calls all the time for that,” said Roy Rogers, a county constable in San Jacinto County. “I go down there and I check it out. If they’re discharging the weapon in a safe manner, there’s nothing I can do.”
The gunfire on Friday took place along Walter Drive, a rutted dirt road outside of the small city of Cleveland, where recent migrants and longtime residents live in closely packed quarter-acre plots, a half-hewn suburban subdivision in the midst of dense woodland.
Like many parts of Texas just outside major cities, San Jacinto County, about 50 miles from downtown Houston, has been rapidly growing.
Residents regularly complained about neighbors firing their weapons, both to the sheriff’s office and on a private community Facebook page, where posts about gunfire go back years.
“Everyone back here’s got a gun,” said Dale Tiller, who lives around the corner from the street where the shooting occurred and runs what he calls a neighborhood watch. He said there had been “a thousand” complaints about gunfire to the sheriff’s office, and that when officers do respond, it often takes them “over an hour” to arrive.
“I’ll be in Galveston drinking a margarita by the time they get here, that’s how long it takes them,” he said.
The sheriff’s office did not respond to a request for records of 911 calls regarding Mr. Oropesa’s address. Officials have previously said he had a history of shooting in his yard, but it was not clear whether he had ever been told to stop by the police.
The frequency with which gunfire was reported, particularly in this area of potholed roads and moldering homes, may have contributed to an apparent lack of urgency in the response to the initial 911 call.
After the killings, Mr. Oropesa fled on foot, officials said. The sheriff, Greg Capers, and his deputies began the search through the neighborhood and the surrounding dense woods where wet, muddy ground presented difficulties for some vehicles.
His deputies were joined by agents from the F.B.I. as well as officers from the state police and sheriff’s deputies from surrounding counties. But the trail of Mr. Oropesa quickly turned cold, after he dropped his cellphone and some clothing on Saturday, officials said.
And there were early stumbles: Looking for assistance from the public, the F.B.I. disseminated an image of Mr. Oropesa on Sunday that turned out to be the wrong person.
On Tuesday, large posters bearing the correct image of the man being sought stared back at drivers from several intersections around San Jacinto County, with text in Spanish offering steep rewards — now totaling $80,000 — for information leading to his arrest.
The search had the entire community of San Jacinto County on edge. The county judge, Fritz Faulkner, said he found his wife sitting on the couch with a shotgun when he returned from being out on Sunday. “We’re just in shock,” he said.
Along Walter Drive on Monday, several young men came to feed unrestrained dogs around the house where the shooting took place. A horse grazed in the grass among chickens on the property where Mr. Oropesa lived with a woman whom the authorities have described as his wife. At one point, a pickup truck left the residence, kicking up dust around the television cameras nearby.
Later, residents gathered for a vigil and placed flowers at the foot of a tree outside the victims’ home. Higher up on the tree was a fading old sign, a kind of no trespassing notice: “Warning: if you are found here tonight, you will be found here tomorrow,” it read, along with an image of two handguns.
The country is full of gun owners, some of whom fire their weapons on their own property. What is unique in Texas is a combination of legal permissiveness, social tolerance and increasing density in rural areas where the freedom to fire guns has been a traditional part of life.
“We had some developments going in that were smaller acreages, two and a half acres and less, and people were putting cans on their fence posts and shooting and the bullets were going across their neighbors’ property,” said Hoppy Haden, the county judge in Caldwell County, a rural area south of Austin. “We chose to regulate that, and you would not believe the amount of pushback we got.”
Despite the new rules there limiting gunfire on small subdivision plots, Mr. Haden said the local sheriff still received complaints about shots fired. Enforcing the new rules can be a challenge. “Somebody either has to video them doing it, or the sheriff’s department has to see them doing it,” he said, likening it to speeding. “It’s frustrating for us.”
No such regulations have been adopted in San Jacinto County, according to Mr. Faulkner, the top elected county official. But that does not mean that residents can legally fire their guns on small plots of land, he added.
“You’re talking about a quarter-acre lot,” he said of the area where Friday’s shooting took place. “That’s not legal in San Jacinto County or anywhere else in Texas. Just because you’ve got a little land doesn’t mean you can be shooting.”
Mr. Rogers, the local constable, said he often found himself debating the Second Amendment with gun owners when responding to neighbors’ complaints over gunfire. Some are aggressive, he said. “They have the constitutional right and they start pleading their Second Amendment rights to me,” he said.
In any case, the rules about boundaries and recklessness would generally preclude firing on small lots, said Richard Hayes, a lawyer specializing in firearms cases in Texas.
“I don’t know how you could shoot on a quarter acre and it not be reckless,” he said. “There’s theoretically not a safe direction to discharge a firearm on such a small piece of property.”
Mr. Faulkner, 63, a lifelong San Jacinto County resident, said he had personal experience with the dangers of errant gunfire between neighbors. In 2004, he said, his wife had been struck in the knee while out pulling weeds on their property. She had been hunched over, he said, and the bullet came within inches of her head.
No one was ever directly connected to the shooting, though Mr. Faulkner said he believed it was a neighbor who has since died. “I heard he was shooting at a squirrel,” he said.