A Nairobi court has dismissed terrorism charges against Worqu Dejene Sar and his father Sar Guracha Haro.
The two had been charged with six terrorism related acts, over twin explosions which occurred in two buses in Githurai in 2014.
Chief magistrate Francis Andayi said the police failed to link the two against the alleged terrorist acts.
The court, however, found Mr Haro guilty of threatening a witness for testifying against his son.
The twin blasts killed three people and injured 67 others.
The busses had left Nairobi and one was heading to Githurai 45 while the second one was heading to Mwiki in Kasarani on May 4, 2014.
The explosives were well-coordinated as they happened one after the other. Two men died in one bus while a woman died in the second vehicle.
The court heard that some improvised explosive devices, which had been planted in the busses, exploded at around 5 pm near Homeland area, while another one went off at the Roysambu underpass.
The police arrested Mr Dejene one week later for allegedly planting the explosives. He allegedly confessed but the court rejected the confession as evidence.
His father was later arrested for allegedly receiving money from Al-Shabaab after the acts but the court said there was no link between the money and the terror group.
The court also said that there was no evidence that Mr Dejene had travelled to Somalia to train as a terrorist.