The boy had surgery at Westmead Hospital on Tuesday morning and remained in a critical condition.
“This is a tragic, tragic incident that has occurred, essentially over nothing; the purchasing of vapes. A young man has been seriously, seriously injured,” Inspector Laird said.
Police said they arrested a man, 18, at Windsor Police Station about 10.30am.
He was charged with assault with intent to rob whilst armed with an offensive weapon and refused bail to appear before Penrith Local Court on Wednesday.
Detective Inspector Laird said the teenager had suffered “catastrophic injuries” and might not be able to tell police what happened.
“The boy only turned 17 the other day; it’s a difficult time of the year for anyone to be involved in tragic traumatic injuries,” he said.
“We owe it to him to investigate all lines of inquiry and we’ll be open to whether it’s a motor vehicle collision or something more sinister, but we won’t rule anything out.”
Detectives are also door-knocking around the neighbourhood and requesting anyone with dash cam footage of the incident to come forward.
Crime Stoppers: 1800 333 000 or nsw.crimestoppers.com.au.
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