Juma was killed on the night of May 5. Police said they found him dead in his vehicle on Lenana Road in Nairobi.
In a series of tweets since December last year, Juma had claimed the deputy president was planning his assassination.
Yesterday, Ruto said Juma was best placed to respond to his own accusations.
“We lost Jacob Juma. He would be best-placed to respond to your question,” Ruto told Citizen TV's Hussein Mohamed on The Big Question show, where he was guest.
“I am sure as the sun rises tomorrow that the killers of Jacob Juma will be brought to book,” he said. “I want to tell Kenyans that I had nothing to do with the killing of Jacob Juma."
Ruto also said former MP Cyrus Jirongo should tell the country why he tried to implicate the deputy president in the killing.
Ruto said the police have not questioned him but he is ready to record a statement.
He complained that he had become a scapegoat for many ills in the country, including marital brawls between Cord co-principal Moses Wetang'ula and his wife.
Ruto said that a certain newspaper claimed the reason Wetangula and his wife fought recently was because she was seen in Ruto's office. “I do not know Wetangula's wife and I have never met her,” Ruto said.
-The Star