But he again declined to lay blame at the feet of Saudi Crown Prince Mohammed bin Salman or his father, King Salman, saying he'd spoken to both of them and they denied any involvement.
"To blame such an incident on a handful of security and intelligence members would not satisfy us or the global community", Erdogan said in a speech to ruling party lawmakers in parliament.
"The Saudi administration has taken an important step by admitting to the murder".
Erdogan had previously promised to detail Turkey's investigation into Khashoggi's killing "in all its nakedness". However, Erdogan did not produce the secret audio recordings that some officials have said provide proof of how Khashoggi was killed.
Erdogan's speech about #JamalKhashoggi's murder fell well short of expectations. However, he kept pressure on the kingdom with his demands for Turkish prosecution of the suspects as well as punishment for the plot's masterminds.
Erdogan added that all information, evidence that has been revealed till now showed that Khashoggi was the victim of a brutal murder. "Covering up this kind of savagery will hurt the conscience of all humanity", he said, per the Washington Post.
On October 19, Saudi Arabia admitted that the journalist had been killed in a fight inside the consulate.
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Khashoggi , a US resident who fled Saudi Arabia past year , was an outspoken critic of Crown Prince Mohammed bin Salman . He said the Saudis did not know how Khashoggi , a Saudi national and US resident, had been killed or where his body was.
One source also suggested Mr Khashoggi's remains were discovered in the garden of the Saudi consul general's home - situated around 500 metres away from the consulate.
He, however, acknowledged Turkey was still searching for answers to key questions, including who gave the order. It was unclear who the 21 Saudis were and whether they include those 18 Saudis, with the State Department declining to name them because of confidentiality laws.
Erdogan offered his "sincere apologies" to the senior scribe's family, fiancee and the people of Saudi Arabia before beginning his speech at the Turkish parliament. The case has shocked people around the world.
The kingdom's announcement that Khashoggi died in a "fistfight" was met with worldwide skepticism and allegations of a cover-up to absolve the 33-year-old crown prince of direct responsibility.
Saudi Arabia had sent a team to Turkey and all those responsible for the journalist's death would be detained, the minister told a news conference in Indonesia.
"Nobody in the kingdom can justify it or explain it". The 15 Saudis knew Khashoggi would enter the consulate to get a document he needed to get married, and once he was inside, the Saudis accosted Khashoggi, cut off his fingers, killed and dismembered the 59-year-old writer, according to media reports.
Khashoggi's death has created a diplomatic crisis for Saudi Arabia as Turkish intelligence links the hitmen to Crown Prince Mohammed bin Salman's inner circle. On video footage he did not appear to be carrying belongings when he entered the consulate that day.
Authorities discovered the vehicle at an underground garage on Monday.