Friends and family who held spaghetti dinners, bowling events and concerts to raise money for Knox's defense were thrilled to have her home, but her supporters were a small presence at the Seattle-Tacoma International Airport compared to the media: dozens of U.S. and international reporters, along with cameras and satellite trucks.
Knox's life turned around dramatically Monday when an Italian appeals court threw out her conviction in the sexual assault and fatal stabbing of her British roommate. On Tuesday a courtroom picture of Knox crying after the verdict was read appeared on the front pages of newspapers in Italy, the U.S., Britain and around the world.
The court's decision, fueled by doubts over DNA evidence, stunned the victim's family and angered the prosecution, which insists that she was among three people who killed 21-year-old Meredith Kercher. But for Knox's grandmother Elisabeth Huff, "it was like the weight of the world had gone."
"We all are as happy as can be. I can't tell you how long we've been looking forward to this day," Huff told The Associated Press outside her home in West Seattle, a tight-knit community a few miles across Elliott Bay from downtown.
"WELCOME HOME AMANDA," read the marquee at a record store in the neighborhood where Knox grew up. Another welcome sign was hung at her father's house. A bar offered half-price drinks to celebrate her acquittal. At least one TV station in Washington state tracked the progress of her flight on the air using a plane-tracking website.
Knox, 24, left Perugia's Capanne prison Monday night amid cheers that a companion compared to those at a soccer stadium.
Hundreds of inmates - most of them in the men's wing - shouted "Amanda, ciao!" and "Freedom!" as she walked into the central courtyard, said Corrado Maria Daclon, head of the Italy-US Foundation, which championed Knox's cause. Daclon said Knox jumped a little for joy and waved to the prisoners.
She was soon on her way home, protected by the darkened windows of a Mercedes that led her out of the prison in the middle of the night, and then Tuesday morning to Rome's Leonardo da Vinci airport. She flew from Rome to London, where she took a direct British Airways flight to Seattle, flying business class with full-length seat and menu options including champagne, smoked salmon and prawn salad.
She and her family were on the plane's secluded upper deck. At least nine members of media organizations were on board below, but a flight attendant blocked them from climbing the stairs "to preserve the privacy" of passengers.
As the plane neared Seattle, the flight crew told reporters that once the plane landed, they would have to remain seated while Customs officials escorted Knox and her entourage out of the plane. "You will not see her," the cabin crew chief said.
Knox's family planned to hold a news conference after the plane landed late Tuesday afternoon, but it was unclear whether Knox herself would speak then.
At the airport, 16-year-old Amra Plavcic shook her head at the dozens of reporters setting up for the news conference, within sight of the gate where Knox's plane was to land.
"I don't think this is important. It's way too much," said Plavcic, who was with her mother awaiting a relative who was on Knox's flight.
Knox was a University of Washington student studying abroad in Perugia when Kercher was killed in 2007.
"Those who wrote, those who defended me, those who were close, those who prayed for me," Knox wrote in a letter released just hours before she left Italy, "I love you."
Knox thanked those Italians "who shared my suffering and helped me survive with hope," in a letter to the Italy-US Foundation, which seeks to promote ties between the two countries.
"We've spent a lot of time waiting," her uncle Michael Huff said in Seattle. "We're planning a big hug. We'll see day to day how it goes. She's going to have to get acclimated. She's a strong kid."
Kerchner's family said during an emotional news conference Tuesday that they were back to "square one."
"If those two are not the guilty parties, then who are the guilty people?" asked Lyle Kercher, a brother of the victim.
Prosecutor Giuliano Mignini expressed disbelief at the innocent verdicts of Knox and her former boyfriend, Raffaele Sollecito. He said he will appeal to Italy's highest criminal court after receiving the reasoning behind the acquittals, due within 90 days.
"Let's wait and we will see who was right. The first court or the appeal court," Mignini told The Associated Press on Tuesday. "This trial was done under unacceptable media pressure."
Prosecutors maintain that Knox, Sollecito and another man killed Kercher during a lurid, drug-fueled sex game. Knox was sentenced to 26 years in prison and Sollecito received 25, but the prosecution's case was blown apart by a DNA review ordered during the appeals trial that discredited crucial genetic evidence.
Prosecutors maintain that Knox's DNA was found on the handle of a kitchen knife believed to be the murder weapon, and that Kercher's DNA was found on the blade. They said Sollecito's DNA was on the clasp of Kercher's bra as part of a mix of evidence that also included the victim's genetic profile.
But an independent review - ordered at the request of the defense - found that police conducting the investigation had made glaring errors. The two experts said below-standard testing and possible contamination raised doubts over the attribution of DNA traces, both on the blade and on the bra clasp, which was collected from the crime scene 46 days after the murder.
The review was crucial to throwing out the convictions because no motive has emerged and witness testimony was contradictory.
The highest court will determine whether any procedures were violated. The hearing generally takes one day in Rome, and defendants are not required to attend.
If the highest court overturns the acquittal, prosecutors would be free to request Knox's extradition. It would be up to the government to decide whether to make the formal extradition request.
One conviction in the slaying still stands: that of Ivory Coast native Rudy Hermann Guede. His lawyer said Tuesday he will seek a retrial.
Guede was convicted in a separate fast-track procedure and saw his sentence cut to 16 years in his final appeal. He says he is innocent, though he admits being in the house the night of the murder.
The highest court, in upholding Guede's conviction, said he had not acted alone. But it did not name Knox and Sollecito as Guede's accomplices, saying it was not up to the court to determine that.
Kercher's family was perplexed. Monday's decision "obviously raises further questions," Lyle Kercher said.
Phuong Le reported from Seattle. Associated Press writers Haven Daley in Seattle, Colleen Barry and Alessandra Rizzo in Perugia, Italy, and Nicole Winfield in Rome contributed to this report.