Tulloch and Parker had originally left Chelsea shortly after the murders, but were gone for only two or three days. Upon returning, they told friends they had left to go rock climbing in Colorado but were forced to turn back when a cut on Tulloch's leg became infected.

Orange County, Vt., Sheriff Dennis McClure said the boys became suspects when authorities learned that one had purchased a military-style knife over the Internet.

The young men came in voluntarily last Thursday for fingerprinting before fleeing.

Warrants were issued for their arrests late Friday and early Saturday.

"All I know is that the prints probably matched enough [from the crime scene] for an identification," McClure said.

Authorities have refused to comment on any possible motive or other connection between the alleged killers and the Zantops.

Robert Tulloch's mother expressed support for her son after his arrest yesterday morning.