SOUTH EL MONTE >> A South El Monte man who killed his neighbor with a meat cleaver and wounded the man’s wife Tuesday “had some sort of delusional belief” that the couple was stealing his Wi-Fi connection, an investigator said Wednesday.

Lt. Victor Lewandowski of the Los Angeles County Sheriff’s Homicide Bureau said 32-year-old Thong Kien Ma also had not slept for three days and that detectives are waiting for the autopsy results to see if there are any drugs in Ma’s system.

Deputies shot and killed Ma after he refused orders to drop the meat cleaver and charged toward them.

Lewandowski said he thinks the two families were neighbors in the 10400 block of Enloe Street for a long time.

Ed Winter, spokesman for the Los Angeles County Department of Coroner, identified the neighbor killed as 59-year-old Chau Da Ngo. Autopsies are pending for Ngo and Ma, he said.

Sheriff’s officials haven’t identified Ngo’s wife. Lewandowski said the woman suffered several lacerations to her head and shoulders that required stitches. He didn’t know if she’s still at the hospital.

No one answered the door at Ma’s home Wednesday. A paper plate with an orange, apple, Asian pear and a kiwi lay on the sidewalk in front of the house. A plate of fruit was also in an altar by the front door and a makeshift altar in the yard.

There were five vehicles parked in the Ngos’ residence Wednesday. A young woman came to the gate and said: “I’m not interested in saying anything.”

Lt. Tom McNeal of the sheriff’s Temple station said deputies had not responded to either house before.

Lewandowski wasn’t sure if Tuesday’s attack started at one house or if Ma came over to the neighbors. A deputy responding to a call of a stabbing found Ngo’s wounded wife. Paramedics took her to a hospital.

The deputy saw Ma standing in a flower bed hacking at something, moved closer and realized he was attacking Ngo, according to Deputy Juanita Navarro-Suarez.

The deputy told Ma to drop the weapon. He raised the meat cleaver and charged at the deputy who shot him, Navarro-Suarez said.

A second deputy arrived. Ma refused to drop the meat cleaver and moved toward the deputies. He was shot again.

Both Ma and Ngo died at the scene.

Miguel Enriquez who lives on Enloe Street didn’t know Ma or the Ngos. He was shocked when he found out about the fatal attack.

“You never see this kind of thing, especially here,” Enriquez said.

This article has been updated from an earlier version to correct the spelling of the suspect’s name.