Washington, Utah, located just south-west of Zion National Park, is surrounded by cinematic, flat-topped mountains and has long been a hub for exploring the natural wonders of the American west.

Yet, the last 48 hours have left residents wondering how the portal to the most beautiful parts of the country may have produced one of its ugliest acts of political violence in years.

Tyler Robinson, the man authorities accused of killing the conservative activist Charlie Kirk at Utah Valley University this week, resided in the area, according to police. He is now in custody after his father apparently persuaded him to surrender.

Local and federal law enforcement officers descended on typically quiet blocks in Washington and nearby St George, banging on doors and closing off streets as they carried out a high-stakes investigation.

Outside the Robinson family home in Washington, neighbours expressed shock that a fellow resident could have committed such an attack.

“It shakes up a community because you don’t expect it,” said Addi Jacobson, 20, who recently moved into her grandmother’s house in the neighbourhood.

Ms Jacobson said she did not personally know the Robinson family, but her grandmother did.

“She just was saying that she thinks that, from what she’s seen and what she knows, they’re a great family, just regular citizens,” Ms Jacobson said. “She used the words, ‘very patriotic people’.”

“We knew their family. Our whole neighbourhood is so close,” said another neighbour who lives around the corner. She asked the BBC not use her name due to the heated political and online discussion Mr Kirk’s murder.

The woman recalled Tyler Robinson “was a pretty quiet kid”, though his younger brothers were more involved in community activities and sports. She called his mother “an amazing parent” and his father “a hard worker”. Both occasionally attended a nearby Mormon church, she said.

“That just even goes to show, you can be an amazing parent, and your kid still just chooses what they choose,” said the neighbour.

“This is a good family,” Utah Governor Spencer Cox told CNN on Saturday. “A normal childhood. All of those things that, that you would hope would never lead to something like this. And sadly, it did.”

On 10 September, Charlie Kirk was shot in front of hundreds of students and observers, and later pronounced dead at the hospital. Videos of the carnage spread across social media, and President Donald Trump, Vice-President JD Vance, and leaders of both major US political parties condemned the assassination.

“If you thought that my husband’s mission was powerful before, you have no idea. You have no idea what you just have unleashed across this entire country,” the activist’s wife, Erika Kirk, said in her first public statement on Friday evening.

The night before Mr Robinson’s arrest, police vehicles descended on a townhouse complex in St George – about 10 minutes from Washington – where local media reported the suspect had an apartment.

Sherri Steele, who lives across the street from the residence, came back from an evening walk to see a large police presence. In a video she showed the BBC, a loud voice, which she said belonged to authorities, can be heard shouting, “Freeze!” and “Come out now!”

“It just kind of blows your mind, coming up the street and all the sudden there are helicopters above your house,” Ms Steele said, adding she had never spoken to Mr Robinson.

Another neighbour, 18-year-old Josh Kemp, said he had seen Mr Robinson leaving his house, on one occasion with a roommate.

According to Mr Robinson’s affidavit, police interviewed a roommate who showed them messages the suspect had allegedly posted on Discord.

The messages discussed a “need to retrieve a rifle from a drop point, leaving the rifle in a bush, messages related to visually watching the area where a rifle was left, and a message referring to having left the rifle wrapped in a towel”.

“The messages also refer to engraving bullets, and a mention of a scope and the rifle being unique,” according to the document.

Utah County Attorney Jeff Gray plans to file formal charges against Mr Robinson on Tuesday, CBS News reported, when the accused will have his first court appearance.

The nation – including the current occupants of the White House in Washington, DC – will be watching.

But Washington, Utah, will, too.

“This whole time, I never knew that I was living next to somebody capable of something like this,” Ms Jacobson said as she played in the park with her fiancé and baby.

“It just makes you kind of question ‘how much closer am I to somebody else that could be this way?'”