Amanda Knox’s return to Italy has been described as “inappropriate” and “very painful” by a lawyer for the family of the murdered British student Meredith Kercher.

Knox was twice convicted and twice acquitted of killing Kercher, 21, in the home they shared in the university town of Perugia in November 2007. The body of Kercher, a student from Coulsdon, Surrey, who was in Italy on an Erasmus programme, was found under a duvet in her bedroom, partly undressed with multiple stab wounds. She had also been sexually assaulted.

Knox has returned to Italy for the first time since being released from prison in 2011, to participate in a conference about wrongful convictions in Modena.

Knox will take part in a debate on the subject of “trial by media” on Saturday. She published an essay on Medium on Wednesday in which she wrote about the “ravenous media” that for years profited “by sensationalising an already sensational and utterly unjustified story”.

She explained why she chose to make her social media accounts public. “The tabloids would lift my photos out of context and call me strange,” she wrote. “I did so because I just wanted to have what every other person around me had, the freedom to shout into the wind and say: ‘Here I am!’”

One of the images that attracted attention was of Knox dressed as Little Red Riding Hood in Germany’s Black Forest in 2017, showing her looking petrified as a man dressed as the Big Bad Wolf stands behind her.

Before leaving her home in Seattle for Italy, she posted a photo on Instagram of her clinging to a mountain edge alongside the caption: “3 Days till I return to Italy for the first time since leaving prison. Feeling frayed, so I made my own inspirational workplace poster. ‘Hang in there!’ Just imagine I’m a kitten.”

She also shared an image of herself with her fiance asking followers to wish the couple a “buon viaggio”.

The Kerchers’ lawyer, Francesco Maresca, said Knox’s reappearances in the public eye were very painful for the family. Knox has previously said she would like to meet the family, visit Kercher’s grave and return to Perugia.

Meredith Kercher, murdered in Perugia in 2007. Photograph: PA

“All these insistences and appearances are only ever done to keep the attention on herself,” Maresca told the Guardian. “The murder is a tragic memory for the Kercher family, they lost their daughter and sister in such a terrible way. It’s also an injustice for them as they still don’t know the full truth.”

He said Knox’s return and involvement in the conference was “inappropriate”, adding: “It’s unjustified because her process was not a classic case of ‘judicial error’. There was a swing in the decisions: some judges decided one way, and others in another way.”

The Kercher family rarely respond to the publicity generated by Knox, who reportedly earned about £3.5m for her memoir, took part in a Netflix documentary about the case in 2016 and has been the subject of other books and films.

On the 10th anniversary of Kercher’s murder, her older sister Stephanie shared a statement with the Guardian. In it she described her strong, determined and caring character, her infectious laughter and her love for Italy. She also wrote: “If nothing else, I can remain sure that the last time I saw her, when I touched her frozen cold body and lay a kiss on her cheek for the last time, the determination to live, the struggle and the fight that she put up on the evening of 1 November despite being outnumbered, was clear to see.”

Knox and her ex-boyfriend Raffaele Sollecito spent four years in prison after initially being convicted of the murder. For Knox, three of those years was for a defamation conviction received after she wrongly accused Patrick Lumumba, a bar owner, of the crime. Lumumba spent two weeks in jail and was only released after someone came forward with an alibi for him. Knox had told investigators that she “covered her ears as he [Lumumba] killed”. She later said she made the allegation as a result of police coercion.

Knox and Sollecito were acquitted in 2011 before being convicted again in 2014 by an appeals court in Florence, which ruled that the multiple injuries inflicted on Kercher’s body proved that Rudy Guede, an Ivorian man serving time for the murder, could not have acted alone. Italy’s highest court overturned the decision in a definitive ruling in 2015, because of what it described as “stunning flaws” in the investigation that led to the convictions.