Story highlights Timothy Burns is charged with arson and two counts of murder

He's accused in the deaths of Atira Hughes-Smith and Jaidon Hill, 7

The sheriff says there's no known relationship between the suspect and victims

A 42-year-old man was charged Wednesday with arson and two counts of murder in connection with the deaths of a woman and her 7-year-old son in Mississippi.

Wearing a bulletproof vest, Timothy Burns appeared in Copiah County Justice Court. He said he has no lawyer, so one will be appointed to him.

No bond was set.

He's being held in the deaths of Atira Hughes-Smith and Jaidon Hill. The boy's stepfather, Laterry Smith, was also killed.

There's some question as to whether Smith was killed in a different county, said Copiah County Sheriff Harold Jones, explaining why Burns was charged with two, rather than three, counts of murder.

There's no indication the suspect had anything against the three victims, the sheriff noted, nor that he even knew them.

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"We don't think there is (a relationship)," Jones said. "But we haven't tied that loose end up yet."

The seeming randomness of the crime makes the deaths all the more inexplicable to loved ones, as well as to neighbors in the city of Brandon they called home.

As Vinson Jenkins, Hughes-Smith's cousin, said: "We don't know why anybody would want to do any harm to them."

The family was last seen Friday in a car that was later found flipped and on fire.

The Copiah County sheriff says authorities now believe that Burns was driving that car when he got in an accident, then set it ablaze. Was he alone at the time? Jones said he has "no way of knowing that right now."

After finding the vehicle, investigators found bloody clothes belonging to the victims next to a gas station trash bin. Then their bodies were discovered in a wooded area, all shot to death, said Jones.

According to CNN affiliate WAPT , Jaidon was a student at Stonebridge Elementary School in Brandon, a city of some 22,000 people about 15 miles east of Jackson.

His teacher Jennifer Owen recalled his omnipresent smile, big eyelashes and how he'd "concentrate on his work so hard that his little tongue would stick out the whole time."

The boy's great-grandfather Sidney Kersh told WAPT that he and others were heartbroken as they tried to make sense of the deaths, especially that of young Jaidon.

"He was my heart, and he was so innocent," Kersh said. "I just hate for him to have to be caught up in this."