A Mexico City teenager has been arrested for killing his 7- and 14-year-old cousins with a knife Sunday during a family party.

Shouting “I’m fed up with trying to be perfect for my mother!” the youth also wounded another 7-year-old cousin and an adult relative at the family gathering in the borough of Venustiano Carranza.

The assailant, identified as Mario, stabbed his 14-year-old cousin 10 times, police said. The cousin was dead when emergency personnel arrived. The 7-year-old, who sustained serious wounds to his abdomen, was taken by ambulance to a nearby hospital, where he later died.

The youth also attacked a 10-year-old female cousin after she shouted to the rest of the family for help. The girl’s 27-year-old mother was stabbed several times when she tried to disarm the youth and was taken by ambulance to a nearby hospital, authorities said.

The youth was finally disarmed by an uncle who persuaded him to give up the knife. The uncle then called emergency personnel.

Authorities told the newspaper El Universal that the 27-year-old female victim said the boy, who lives with his mother, suffered from neglect.

Mexico City Attorney General’s Office spokesperson Ulises Lara López said the youth was in custody and undergoing psychiatric and toxicological evaluation. In addition, he said, the city’s DIF family services agency had been notified and was working in conjunction with authorities on behalf of the minors involved, to investigate the home where the attack occurred.

Source: El Universal (sp)