UN special rapporteur for extrajudicial summary or arbitrary executions Monday slammed Saudi Arabia court rulings in the criminal probe of journalist Jamal Khashoggi as "mockery."

The public prosecutor’s office in Riyadh earlier in the day announced that five people had been sentenced to death for involvement in the killing and three others sentenced to a total of 24 years for their role in covering up the crime and violating law. 

Khashoggi, a columnist for The Washington Post and a U.S. resident, was murdered after entering the Saudi Consulate in Istanbul on Oct. 2 of last year on a visit to pick up paperwork for his forthcoming marriage.

"Bottom line: the hit-men are guilty, sentenced to death. The masterminds not only walk free, they have barely been touched by the investigation and the trial," Agnes Callamard said on Twitter. "That is the antithesis of Justice. It is a mockery."

She reiterated that Saudi kingdom was responsible for the Khashoggi's execution under international human rights law, adding that the trial in Riyadh "at no point" considered the Kingdom's responsibilities.

Callamard also said Riyadh did not investigate the role of Crown Prince Mohammed bin Salman, adding the judge appeared to have concluded that the Khashoggi death was "an accident since there seems to be no intent".

"To suggest that on the spare of the moment, the killers decided to cut down his body is utterly ridiculous. Dismemberment requires minimum planning," she wrote.

"The presence of a forensic doctor enrolled in the official killing team at least 24 hours before the crime, and discussing dismemberment 2 hours before it actually occurred, also clearly indicates planning," said Callamard.

Prosecutor Shalaan al-Shalaan said 11 people have been put on trial in connection with the Khashoggi's killing. He said former royal adviser Saud al-Qahtani was investigated and was not charged in the killing.

Al-Shalaan said Mohammed al-Oteibi, the former consul-general in Istanbul, was also not charged and released because "he was not at the consulate at the time of the killing."

"Impunity for the killing of a journalist commonly reveals political repression, corruption, abuse of power, propaganda, and even international complicity. All are present in Saudi Arabia killing of Jamal Khashoggi," Callamard added.

Turkish Foreign Ministry also decried the ruling and said it "falls far short of expectations."

“The decision is far from meeting the expectations of both our country and the international community for enlightening all aspects of this murder and for the manifestation of justice,” Hami Aksoy, the ministry spokesman, said in a written statement.

Khashoggi's fiancee Hatice Cengiz was also upset and unsatisfied saying on Twitter that "Saudi announcement not acceptable ..! #justice_for_jamal."

In a report in May, Callamard's office concluded that the murder of the prominent journalist was a “deliberate, premeditated execution,” and called for bin Salman, also known as MbS, to be investigated.