CHICORA — A potential key witness has emerged in the case of a Saxonburg man accused of dousing his former girlfriend’s 7-year-old son with nail polish remover then recording the boy after he was set on fire, authorities said.

The witness, a teenage boy, was present May 25 when 36-year-old Edward Myers Jr., with the help of his own two sons, attacked the victim, according to Saxonburg police Chief Joe Beachem.

“As part of our ongoing investigation,” Beachem said this morning, “we found a last-minute witness who has information about this case.”

The sudden disclosure of prospective new evidence delayed Myers’ preliminary hearing Tuesday before District Judge Lewis Stoughton in Chicora.

“We have a third-party witness that we need to interview,” prosecutor Russ Karl, a Butler County assistant district attorney, told Stoughton in requesting the delay.

The judge approved the request and continued Myers’ hearing until Aug. 13.

Myers, who remains in the county prison on a $250,000 bail, is charged with aggravated assault, attempted simple assault, reckless endangerment, and possession of a controlled substance and drug paraphernalia.

According to court documents, Myers, a single father, had been supervising the 7-year-old boy as well as his own two sons, ages 15 and 11, when the alleged assault occurred at his mobile home on Carol Drive.

Myers and his sons allegedly shot airsoft and pellet guns at the 7-year-old’s forehead. Myers later poured nail polish remover over him, police said.

The boy told investigators that his shirt was then intentionally lit on fire by either Myers or the defendant’s older son.

The 15-year-old also faces juvenile charges in the alleged attack.

The victim suffered third-degree burns on his face and chest, covering about 10 percent of his body, documents said.

Police allege Myers did not seek medical help for the boy.

The boy, according to Beachem, suffered in pain for three to six hours until his mother, Laure Halliwell of Saxonburg, returned home and took him to the hospital.

Following Tuesday’s court proceedings, Karl said he only learned of the potential new witness that same day from Saxonburg police.

Beachem said he spoke briefly to the witness for the first time on Monday at the boy’s home. The teen’s parents were also there.

Asked if the boy was in Myers’ trailer and saw the attack, Beachem replied, “That’s the indication we got.”