He had earlier pleaded guilty to the representative charge and not guilty to the other three.
However, he was found guilty of these and convicted by Judge Bridget Mackintosh.
"There is no basis to suggest these injuries were caused as the result of an accidental injury prior to going to bed.
"The only logical and credible inference is that the defendant caused this grievous bodily harm."
Judge Mackintosh said she accepted earlier evidence given by a young family member who had seen Sciascia hit the baby with a cellphone on her head a few days prior to her death, on October 3 and 4, 2019.
"When he hit her, there was a red mark on her head that lasted for about four minutes."
These assaults were not believed to have contributed to her death as the bruises and bleeding on the brain was "fresh" according to the pathologist.
This meant they would have occurred hours before her death, as opposed to days.
The pathologist also found she had multiple injuries in different parts of her brain.
"Substantial force would have been required to inflict those injuries," Judge Mackintosh said.
The injuries also could not have been caused accidentally the day before Maraki's death, she said.
Photo and video evidence showed "all was well" and that Maraki had spent the day playing with and being cared for by family, including her father.
She had exhibited no signs of distress, concussion or semi-consciousness, which would have alerted family to her having sustained a serious injury, before being put to bed.
"She did not have these injuries at 9pm. The only logical inference is that they were received after that."
Sciascia was remanded in custody until his next appearance, a sentencing, in June.
