Tell MAMA UK The “Punish a Muslim Day” letters were sent across the U.K. this spring and urged people to commit acts of violence against Muslims on April 3.

A British man has pleaded guilty to creating a racist letter campaign that called for violence against Muslims and ethnic minorities.

David Parnham, a 35-year-old from central England, admitted that he sent “Punish a Muslim Day” letters that designated April 3 as a day to terrorize British Muslims. The letters assigned various points to specific acts of violence ― from 25 points for pulling Muslim women’s headscarves to 1,000 points for bombing a mosque.

Parnham pleaded guilty in London on Friday to 15 offenses, including soliciting murder and staging a bomb hoax. He faces a potential life sentence, the BBC reports.

The “Punish a Muslim Day” letters rattled British Muslim communities and sparked calls for extra vigilance on that day. The campaign also inspired acts of solidarity, with thousands of people on social media chiming in with hashtags such as #LoveAMuslimDay and #WeStandTogether.

April 3 passed without a significant rise in anti-Muslim violence, Reuters reports.

georgeclerk via Getty Images David Parnham, who admitted to creating the racist campaign, pleaded guilty on Oct. 12 to 15 offenses at the Central Criminal Court in London, also known as the Old Bailey.

The two-year letter campaign began in June 2016. Some of the letters were packaged with a suspicious white powder that turned out to be harmless. The earlier letters targeted British prime ministers and Queen Elizabeth. In the spring of 2017, letters calling for violence against Muslims were sent to mosques around the U.K. This year the “Punish a Muslim” letters that laid out a points-based system for violent acts were sent to mosques and at least four South Asian British politicians.

Parnham was arrested in June after police analyzed DNA and fingerprints from some of the letters.

News media in Parnham’s hometown reported that he worked for the local government.

“Punish A Muslim Day” letters are being sent to families in East London. The letter details a point system for each action & a reward. For example pulling a Muslim women’s hijab is 25 points, throwing acid is 50 points and burning or bombing a mosque is a whole 1,000 points. pic.twitter.com/6kmCrDrXt0 — Rowaida Abdelaziz (@Rowaida_Abdel) March 9, 2018

According to the BBC, one of the “Punish a Muslim Day” letters was sent to Dylann Roof, the avowed white supremacist on death row for killing nine black parishioners at South Carolina’s Emanuel AME Church in 2015.

Tell MAMA U.K., an organization that tracks anti-Muslim hate crimes, said it believes Parnham was “obsessed” with Roof ― pointing out that the date chosen for “Punish a Muslim Day” coincides with his birthday.

Fiyaz Mughal, Tell MAMA U.K.’s founder, said in a press statement on Saturday that his organization welcomed Parnham’s arrest and admission of guilt.

“[Parnham’s] actions also show how the menace of far-right extremism has impacts on communities and cohesion,” Mughal said. “We must remain vigilant going forward.”

The U.K.’s Home Secretary Sajid Javid said on Twitter that he is glad to see Parnham being brought to justice.

“Hate crime has absolutely no place in British society,” Javid wrote on Saturday.