A shopper says a young boy asked if he would be in trouble after allegedly stabbing a Coles worker.

Lee McCann chased a 13-year-old boy police allege attempted to murder 63-year-old Claudia Campomayor at Yamanto Central in Ipswich on Monday.

“I heard a scream and saw the boy run straight past me,” McCann said.

“I paid attention to where the scream came from and recognised that it was a Coles worker that I actually knew.

“I was able to go and chase after him and see if I could hunt him down.”

Two men flanked him as they raced out of the supermarket.

“I’d questioned people along the way and then I was told that he’d actually entered Kmart,” McCann said.

“That’s when they located him at the self-serve checkouts, he was just sitting there.”

McCann said the accused teenager did not put up a fight.

“He was fairly calm, a bit nonchalant, which was a bit disturbing,” he said.

“I questioned him about why he was running, he said that he was scared, he’d seen someone stab someone with a knife.

“While we were walking he asked me if he was in trouble.”

When McCann marched the boy back to Coles the reality of the situation was laid bare. 

“That’s when I saw the employee on the floor with a knife in her back,” he said.

“She was in and out of consciousness, she wasn’t reacting to anything I’d said.”

Campomayor was rushed to the Princess Alexandra Hospital with critical injuries.

In the first steps on the road to recovery, the supermarket employee was awake this morning and spoke briefly with her son.

Police are still investigating.