One post read: "Come today to the Maccy's at 4 o'clock at Olympia Einkaufszentrum.
"I'll give you something if you want, but not too expensive."
German cops confirmed the killer hacked the account to lay his devious trap.
The German citizen, whose parents are Iranian asylum seekers, posted another message saying:
"You can talk to me at McDonald's. I'm here at 4pm. Everyone should come."
Lukas Re warned people the offer was too good to be true and should stay away from the fast food joint.
He said: "The guy is disturbed mentally and just wants attention. If someone is already there can he confirm that there is no Selina."
Sonboly waited in the restaurant before gunning down his innocent victims.
The victims were aged between 13 and 45 – seven of those killed were teenagers.
Ten people remain in a critical condition, with 30 others injured.
Chilling footage emerged showing where Sonboly pulled the illegally purchased 9mm Glock, taking
aim at innocent people as they walked towards McDonalds.
He then entered the Olympia Einkaufszentrum shopping centre where he continued his rampage with more than 300 bullets for ammunition.
The killer was shot by a plain clothes officer, but managed to escape about a kilometre away.
Sonboly then took his own life by shooting himself. Cops found evidence at the boy"s home which showed an unhealthy obsession with far-right
There is no suggestion the boy was influenced by Islamic State or other terrorist organisations.
Reportuk.org through dailystar.co.uk