CLAY, N.Y. – A student who vanished Nov. 19 while on Thanksgiving break in her hometown was killed by her on-again, off-again boyfriend, who dumped her body in a park “like garbage,” an Onondaga County prosecutor said Saturday.

District Attorney William Fitzpatrick said Steven Pieper of Liverpool, N.Y., had been arrested on a charge of murder in the death of Jenni-Lyn Watson, a junior dance major at Mercyhurst College in Erie, Pa. He was slated to be arraigned Saturday night in Clay town court.

No phone number was listed at Pieper’s home address. A message left at a relative’s house was not immediately returned Saturday. It was unclear whether he had an attorney yet.

Fitzpatrick said Pieper, 21, was upset when Watson, 20, tried to end their relationship.

Watson’s parents have been notified, and an autopsy was expected to be performed today, Fitzpatrick said.