Complex sentence: Under Serco, there has been an increase of deaths in custody, self-harm, and of Serco staff beating prisoners, as well as a deterioration of facilities leading to the decline of the physical and the mental health of detainees and of staff.
Split into simpler sentences: Under Serco, there has been an increase of deaths in custody, self-harm, and of Serco staff beating prisoners. As well, there has been a deterioration of facilities leading to the decline of the physical and the mental health of detainees and of staff.