Charlie Kirk’s assassin Tyler Robinson had become increasingly political in recent years — and seethed about his victim’s upcoming campus appearance just before killing him. officials said Friday.

Robinson, a 22-year-old former student at Utah State University, was enraged over Kirk’s visit to Utah Valley University on Sept. 10, making his ire clear during a dinner with relatives days before he fatally shot the close friend of President Trump, authorities said.

The suspect, who was not registered to any political party, went on to spout off about how he “didn’t like [Kirk] and the viewpoints he had,’’ said Utah Gov. Spencer Cox at a press briefing.

A relative also shared what he didn’t like about Kirk — claiming the victim “was full of hate and spreading hate,” according to Cox and an affidavit.

The killer was turned in by his dad through a minister who was a family friend, officials said.

Robinson at first told his dad he’d rather kill himself than surrender, law-enforcement sources said.

Three unfired casings found in the chamber of the rifle reportedly used by Robinson included left-wing slogans such as “Hey fascist! Catch!” engraved on the side along with an up arrow, a right arrow and three down arrows.

Another featured the words “Oh bella ciao, bella ciao, bella ciao ciao ciao,” referencing a popular Italian anti-fascist song, Cox said.

A third casing, engraved “If you read this, you are gay LMAO [laughing my a– off]” was found in the chamber of the weapon, a Mauser model 98 bolt-action rifle with a scope mounted on it.

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The inscription on the fired casing read, “notices, bulges, OWO, what’s this?” Gov. Cox said.

Photos of him shared by his mother on social media seem to show a normal, happy family.

Pictures show the parents and their three kids enjoying trips to gun shows, vacations at theme parks, and sporting events.

There is no indication of a prior criminal record, a search of state and national public records shows, as authorities continue to build up a picture of Robinson’s actions and words in the days leading up to the shooting.

Authorities interviewed Robinson’s roommate, who showed them Discord messages from a contact named “Tyler” that included the need to retrieve a rifle and where the rifle was left wrapped in a towel, Cox said.

Other messages allegedly from Robinson said that he had changed his outfit in the wake of the shooting, Cox said.

Robinson was turned in after his father recognized him in photos released by the FBI on Thursday, law enforcement sources told The Post.

The father called the Washington County Sheriff’s Department and confronted his son when he returned home, at which point Robinson admitted he was the gunman, the sources said.

Robinson’s father asked him to turn himself in, but his son replied that he would rather kill himself.

The father then convinced his son to speak with their youth minister, who also serves as a task force officer with the US Marshals Service.

The minister called the FBI and agents later took Robinson into custody.

“We got him,” declared Gov. Cox as he opened Friday’s news conference, where he was joined by FBI Director Kash Patel, as they announced that the 33-hour manhunt finally came to a close Thursday night.

Director Patel concluded his remarks with an emotional tribute to his friend, Kirk, saying, “See you in Valhalla.”