Help Out, It's A Psychological Illness

Nairalanders please help out. What would you do if you were unfortunate to be at a place when at that time, a man is being murdered in cold blood by another man (note that the killer thought nobody was there), you shouted due to the horrible scene and u are being chased. Even though you are not caught, it always occur to you that somene is somewhere planning to kill you, that u are even very careful of walking alone,  What can I tell the person involved?

hes got to talk,let others share his fears and worries with him.let him talk with a social worker or a counsellor.too bad witness protection programme doesnt exist in Nigeria  it would have been easier.