A St Catherine man who was charged with assault for allegedly attacking his girlfriend during a dispute and allegedly injecting her with a toxic substance has now been charged with murder as the woman has succumbed.He is 51-year-old Paul Stephenson, also known as 'Pablo', of New Harbour Village, St Catherine.The deceased has been identified as 29-year-old Tieah Singh of Old Paisley district in May Pen, Clarendon.The police report that about 10:00 a.m. on Tuesday, June 9, Stephenson and Singh had an argument.