anarda de la caridad 37 , is said to have been ` suffering from post-natal depression ' when she allegedly stabbed shannon , 31 , the couple 's six-week-old baby and her daughter , four .
mr shannon , from liverpool , had initially been accused of killing his partner and the two children , but police now believe perez friman , a spanish national of cuban descent , to be the culprit .
mr shannon 's body was found with defensive wounds which suggest that he has been trying to protect the children before being killed .