Journalist John Kercher, 70, spoke out after US student Amanda Knox, 26, and her former boyfriend Raffaele Sollecito, 29, were found guilty for the second time last night of the killing of the exchange student.
The retrial reversed an earlier appeal judgment and means Knox's sentence has been increased to 28 years and six months and Sollecito's to 25 years. Knox is currently in the US after winning her previous appeal.
Mr Kercher said: "No matter what the verdict, it was never going to be a case of celebrating anything.
"That's probably the best we could have hoped for."
Meredith's sister, Stephanie Kercher, added: "We didn't know what to expect. We are still in shock."
The victim's brother Lyle Kercher said he found it difficult to forgive Knox and Sollecito, adding: "I think you'd have to be a very strong-willed - arguably religious - person to find that forgiveness.
"I think it is so easily forgotten what happened to Meredith. When I read reports even now, I find myself skimming past the paragraphs that refer to what happened to her because it is so horrific."
Knox continued to protest her innocence and claimed there had been a lack of evidence to convict her of killing Meredith, who was found stabbed to death at the house where she was staying while studying in Perugia in November 2007.
She said: "I am frightened and saddened by this unjust verdict. Having been found innocent before, I expected better from the Italian justice system. The evidence and accusatory theory do not justify a verdict of guilt beyond a reasonable doubt."
Knox said her thoughts were with Meredith's family, who deserve "respect and support".
Knox's lawyer, Luciano Ghirga, said she will launch an appeal against the decision, but admitted Knox hung up the phone after learning the news. Mr Ghirga said: "For those who, like me, are convinced that Amanda is innocent, it is a very difficult time.
"We have to respect the verdict but we will challenge them. We're very sad at the moment. We will definitely try everything.
Sollecito's lawyer Giulia Bongiorno confirmed that her client would appeal to Italy's highest court. The court will publish the reasons for its verdict in 90 days' time.
Jurors had been deliberating for 12 hours before they emerged to confirm Knox and Sollecito's original 2009 conviction.
If final appeals are heard, Sollecito, who is banned from leaving Italy, would face arrest or jail time until a final verdict by the highest court.
Knox would have to be extradited from the US to serve her sentence.
Ms Kercher, 21, of Coulsden, Surrey, lived with Knox, who was a fellow student. After her murder, investigators quickly pointed to Knox and Sollecito as suspects, building a narrative that the two killed Ms Kercher in a sex game gone awry. Both were convicted in 2009 and spent four years in prison.
They were cleared on appeal, but Italy's highest court last year quashed the verdict due to "inconsistencies" and ordered a repeat of the appeal trial.