LONDON (AP) — A former British cyberespionage employee who had become angry and resentful toward his agency’s work was sentenced Monday to life in prison for attempted murder in the vicious stabbing of an American intelligence worker assigned to the U.K.

Joshua Bowles, 29, punched the woman and knifed her repeatedly in what was called a “politically motivated” attack as she left a gym March 9 in the western England town of Cheltenham, which is home to the U.K.’s electronic spy agency, Government Communications Headquarters, better known as GCHQ.

“I’ve just tried to kill her,” Bowles said, according to Steve Bunn, who helped stop the attack. “It’s ... good ... I didn’t have a gun, isn’t it? I make a pretty (expletive) terrorist, don’t I?”

Bowles will serve at least 13 years in prison before any chance at early release.

The woman, identified in court only by a code number, 99230, worked for the National Security Agency, which spies on electronic communications for the U.S., and places some of its employees at the Cheltenham facility.

Prosecutor Duncan Penny said the attack was pre-meditated and the woman was targeted solely because of her role with the NSA.

“American intelligence represents the largest contributor within the intelligence community, so (it) made sense as the symbolic target,” Bowles told police after his arrest. “I consider GCHQ just as guilty.”

Justice Bobbie Cheema-Grubb in London’s Central Criminal Court called it a “politically motivated attack” driven by “anger and resentment” towards GCHQ and women. The judge said Bowles, a former computer software coding developer, had shown a “deep disaffection with society and a desire to challenge authority.”

Bowles’ internet searches included white supremacy, Unabomber Theodore Kaczynski and attacks on women.

“By the time you launched your attack, your feelings of anger and resentment against GCHQ and women had evolved sufficiently to lead you to mount a lethal assault through which you wanted, however unrealistically, to disrupt the work of the U.K. intelligence community with an important ally, the United States of America, and you hoped to achieve this by killing one of the American citizens you knew was engaged in that work,” Cheema-Grubb said.

After Bunn intervened, he said Bowles told him he would understand his actions if he knew what was being done at GCHQ and said he was appalled by the work of the NSA.

“He was disgusted by the manner in which they gather information and use things against people,” Bunn said, and said he could no longer “handle the murky waters of ethics and whether they are doing the right thing and the power that the American NSA have and the things they do.”

Defense attorney Tim Forte said Bowles had “profound regret, remorse and shame at what he has done.”

Forte said his client was not a terrorist but was depressed at being rejected by another former American co-worker he liked and trying to hurt GCHQ.

The victim recovered after being hospitalized for cuts to her abdomen, chest and thigh. She said it had a profound effect and “completely changed my life.”

She said in a victim impact statement that she felt sick using Bowles’ name.

“I now know he used to work where I work and I’m devastated by this,” she said. “Following the attack, I went from being in the best shape I had ever been to being the weakest I have ever been.”

The woman and a female U.S. colleague were leaving the gym after a game of netball, a sport similar to basketball, when Bowles walked up behind them and said “Excuse me.”

Bowles punched her in the face repeatedly when she turned around. She kicked and screamed, and her friend hit Bowles with her bag.

Alex Fuentes, a man on his way to play soccer, tried to intervene and was punched in the face, allowing the women to run to the health club entrance, where Bowles chased them and lunged at the woman with one of the two knives he carried, according the prosecutor.

“It felt like he hated me … his focus was me,” the woman said, according to Penny.

The attack ended when Bunn, who was at the gym, restrained Bowles.

Detective Chief Superintendent Olly Wright, who is a head of counter-terrorism policing, said the intervention probably saved the woman’s life.

“Despite the brave efforts of members of the public who intervened during the attack, Bowles remained completely undeterred,” Wright said.

A GCHQ spokesperson said the agency was satisfied that justice had been served, calling it “a shocking, unprovoked attack, and its isolated nature does not make it any less upsetting.”

An NSA spokesperson said the agency was committed to the safety of its employees and would continue providing support to the victim.