Here's more details from Egypt Today:
The late bishop was found dead and covered in blood on Sunday morning. The preliminary security investigation suggested that Bishop Epiphanius was hit by a sharp object. The body of the bishop was transferred to the morgue of the Wadi El-Natrun Central Hospital.
Monk Basil of the St. Macarius Monastery told Al-Watan that 130 monks live in the monastery and that the body of Bishop Epiphanius was discovered by Monk Gabriel. A part of Epiphanius’s brain got out of his skull which enhances the probability that the bishop was hit by a sharp object.