Nathan Alexander Sanchez, 6

Nathan Alexander Sanchez, a 6-year-old Latino, was found dead Thursday, Sept. 18, in the 1600 block of East 88th Street in Florence-Firestone, according to the Los Angeles County Sheriff’s Department and family members.

Authorities said the child was found stabbed on a bed inside a small white trailer behind a home.

Concerned neighbors called 911 shortly after midnight because they heard a man yelling and screaming, said sheriff’s Lt. Eddie Hernandez. Once deputies arrived, they found 38-year-old Alejandro Sanchez-Santoyo, the boy's father, covered in blood in the frontyard and "speaking incoherently."

A neighbor directed authorities to the trailer, where they performed CPR on the child before paramedics arrived. The boy was taken to St. Francis Medical Center, where he was pronounced dead at 12:39 a.m., said Ed Winter, assistant chief of investigations with the coroner's office. A kitchen knife was recovered at the scene.

Hernandez said the father, who was detained and questioned for several hours Thursday, was arrested on suspicion of murder.

The man’s sister, Yolanda Sanchez-Santoyo, 47, said she was shocked. “He was my nephew and I loved him very much,” Sanchez said.

Sanchez said she had spoken to her brother about taking custody of her nephew because he was often away, but he always refused. She said Nathan’s mother died five days after he was born.

“This is a double heartbreak,” Sanchez said.

Six houses away from the scene, Ernestina Quintero, 50, described Nathan Sanchez as a happy, outgoing and curious child. She baby-sat the child for about two years.

“He couldn’t sit still for a moment,” she said. “I’m terribly sad over this.”

She said the boy attended Parmelee Avenue Elementary School off East 76th Place and Hooper Avenue.

In May, she said she took the boy to Disneyland for the first time.“He didn’t want to leave,” she said. “He was so happy.”

Sitting on her front porch Thursday afternoon, she stared at the small swimming pool the boy had been using the day before.

“His father came and picked him up and he just said bye,” she said. “I just wouldn’t have ever imagined that his father would do that.”

Investigators say they are still trying to determine what led to stabbing. Authorities do not know whether the suspect was under the influence of drugs or alcohol.

“He’s the best lead we have as to what may have occurred,” Hernandez said.

-- Ruben Vives and Nicole Santa Cruz

Update, Sept. 19: This post has been updated to include additional information from the coroner's office including Nathan Sanchez' middle name and the time of death.