Xavier Zamora, 17, of Albuquerque, is charged with murder and charged with killing postman Jose Hernandez on Monday afternoon.
Hernandez was working in southwestern Albuquerque when he saw Zamora in an altercation with Zamora's mother in front of her home, and decided to help her escalate the fight, police said in Albuquerque.
Hernandez sprayed Mace on Zamora as the teenager became aggressive, the police said, citing an interview with the mother.
The teenager then went to his house, came out with a gun, and shot Hernandez in the abdomen before returning, police said.
Someone tried to revive Hernandez, but the 47-year-old postman and army veteran eventually died of his wound.
The police were called and SWAT officers surrounded the house. Although no one had seen Zamora leave before the officers arrived, the police finally learned that Zamora had fled, the police said.
Zamora is 6 feet tall, has brown hair and brown eyes and weighs 165 pounds according to a warrant
Everyone in the neighborhood knew the postman, a resident says
Postman, "said Michael Shepherd KOAT." He would go out of his way. He would talk to you. "
On Tuesday, people left flowers and notes outside the house in Hernandez's memory, KOAT reported.
" To a great postman who sacrificed his life for the sake of the greater good "We will all remember you."
Hernandez, a forwarder at the city's Five Points Post Office, worked for the US Postal Service for 12 years, said the agency.
"We are shocked and saddened to learn of such a tragic death of one of our own employees and associates," said the spokesman for the postal service, Rod Spurgeon. "He served his congregation with devotion and was an excellent one Veteran of the army.
"Our thoughts and prayers are with his family at the time, and the postal service is providing assistance services to his family and staff."
Mayor Tim Keller shook the city, "said Mayor Tim Keller.
" We mourn with the victim's family and with the entire postal service family, "Keller said. As we work to find answers to the many remaining unanswered questions, we know that we must and must fight the armed force that has challenged our community to a terrible degree. The fight against crime will continue to be a top priority.
"Albuquerque, please take some time over the next few days to personally see that your mailman in your area knows how much you appreciate him and give them your love and support."
Amanda Watts and Casey of CNN Hicks contributed to this report.