my sister was physically attacked yesterday by someone she knows. It was a very minor argument but the other party just lost the plot and started attacking her and bit her finger. This was outside a shop and other people intervened to drag the other party off my sister when they heard her screaming. My sister reported it to the police but they are not taking any further action because the witnesses didn't see the initial attack. also the police didn't interview all the witnesses as they had left the scene when they arrived. can we pursue any civil case against the attacker? Is it worth it?