Edgar Maddison Welch, 29, also received 36 months of probation and was ordered to pay $5,744.33 in restitution for firing three shots with an AR-15 rifle inside the Comet Ping Pong restaurant in northwest Washington in December. He claimed he was attempting to find and rescue child sex slaves that he believed were being held at the restaurant -- a belief allegedly based on his reading of a false story circulating online that connected Hillary Clinton's campaign adviser to the pizzeria through coded messages in his leaked emails.
After Welch found no evidence of child sex-trafficking at the restaurant, he did not harm anyone and surrendered.
He pleaded guilty to gun charges in federal court in March.
Despite Welch's minimal criminal history, the sentence far exceeded the defense's case for a shorter, 18-month term, as well as the average 37-month sentence for a defendant of "similar charges," according to Judge Ketanji B. Jackson.
"The extent of recklessness in this case is breathtaking. It is sheer luck that no one, including (Welch), was killed," Jackson said, adding, "I've never seen anything like the conduct we see here today."
Jackson said she believed Welch had good intentions, but deemed his actions "an assault on the rule of law" that could potentially inspire future "ill-conceived plots" by vigilantes.
Welch's family was present at the sentencing. His former girlfriend, who said she attempted to talk Welch out of his actions when he revealed them to her, teared up when the prosecution played a short clip of a two-minute video Welch had recorded in the car on his way to Comet to say goodbye to his two young daughters.
Three witnesses offered statements Thursday, including James Alefantis, founder and owner of Comet Ping Pong, whom Jackson cited in her closing remarks for his discussion of psychological trauma.
"I do hope that one day, in a more thoughtful world, everyone of us will remember this day as an aberration ... when the world went mad, and fake news was real," Alefantis said.
Two Comet employees said they were traumatized by the incident.
But several of witnesses forgave Welch. In her opening remarks, assistant federal defender Dani Jahn thanked the victims for their "humanity." She choked up and paused to collect herself before proceeding.
Many victims blamed fake news websites that had promoted the conspiracy.
"I hope you realize that you have been a pawn of the misguided media," a witness said.
Several witnesses also requested that Welch receive a mental health evaluation, which Jackson later affirmed. This became a point of tension when Jahn challenged the mental health evaluation stipulation, noting that the record showed no evidence of Welch's mental illness. After a sharp back-and-forth with Jackson, Jahn agreed to the terms.
At one point, Welch spoke for a few moments to offer an apology.
"I'm sorry for everything I've caused," Welch said.