"He (the father) is a man whose life is in ruins. I felt incredibly sorry for him as he expressed all his emotion, he expressed his emotion because he has lost a loved one, but also because his son is perhaps the (cause) of all this tragedy," he told BFM news channel.
"I have great respect for this man who despite himself is at the centre of a tragedy that he did not seek," said Mr Bartolini.
Hours before Thursday's memorial ceremony, French prosecutors announced that they believe Lubitz deliberately slammed the Germanwings flight into a mountain on Tuesday.
Officers removed bags of items that included a computer from the family home.
Lubitz also had an apartment in Dusseldorf, which was the destination of the doomed Germanwings flight that had departed from Barcelona.
Dusseldorf prosecutors say Lubitz hid evidence of an illness from his employers - including a torn-up doctor's note that would have kept him off work the day authorities say he crashed Flight 9525.
Searches conducted at Lubitz's homes in Duesseldorf and in Montabaur turned up documents pointing to "an existing illness and appropriate medical treatment," but no suicide note was found.
German media have reported that Lubitz had received prolonged treatment starting in 2008 for a "serious depressive episode".
