Magomed Yevloyev, who ran a banned website that had called for protests against the local government, was shot in the head on August 31 while in a police vehicle. He died in hospital. Police claimed that an officer's gun had gone off "accidentally."
A criminal case into manslaughter was opened. Opposition groups claimed this was a political murder.
The lawyer representing Yevloyev's family, Musa Pliyev, said: "This ruling is unlawful...The judge has been under pressure and made the decision directed by her own thoughts not by the law."
Pliyev added they would appeal the ruling through the Supreme Court of Ingushetia.
Yevloyev was arrested at the airport after his plane landed in Ingushetia. His death triggered mass protests in the North Caucasus republic.
Widespread media speculation said that before his arrest and subsequent death the journalist had been involved in a mid-air dispute with Ingush President Murat Zyazikov, who was travelling on the same plane as Yevloyev.
Ingushetia has seen a rise in violence in recent months. The Russia-based human rights group, the Moscow Helsinki Group, said in late September that the republic was on the verge of civil war as fighting between militants and authorities intensified. It also accused federal authorities of torture and abductions.
