The state prosecutor at the trial in Paris called for Dekhar to be jailed for 25 years for attempted murder and for two-thirds of the time to be non-commutable.
On 15 November 2013 Dekhar marched into the offices of the BFMTV station, threatening a security guard and journalists, firing the shotgun at chief editor Philippe Antoine and telling him, "Next time I won't miss you."
Three days later he shot photographer César Sébastien, who was 23 at the time, in the back at the offices of Libération newspaper.
He then went to Paris's La Défense business district and fired shots at the headquarters of the Société Générale bank before forcing a motorist to help him escape.
He was found on 20 November in a carpark in a town near Paris after a friend who had been putting him up tipped off police.
Accomplice of cop-killers
Dekhar has already served a prison sentence for being the accomplice of two anarchist lovers, Florence Rey and Audry Maupin, who killed three police officers in a shootout in Paris in 1994.
A taxi driver also died, as did Maupin.
Dekhar claimed political motives for the 2013 attacks, saying in court that he had been particularly bitter to see Libération move from the left to "singing the praises of neoliberalism".
But he also said he had "confused my despair with my politics" and wanted to commit "suicide by proxy", hoping the police would kill him and give him a "romantic death".
After leaving jail, Dekhar had managed to lead a normal life until family problems pushed him back over the edge in 2013, prosecutor Bernard Farret said.
Investigators described him as a "pathological liar".
He harboured "resentment against society, the state and capitalism", as well as a "desire for vengeance", according to Farret.
The state also called for Sébastien Lemoine, who had housed Dekhar before tipping off police, to be given a suspended prison sentence.