PORTSMOUTH, N.H. – One of two women accused of drowning a dog in a bathtub in what was supposed to be a “mercy killing” has pleaded not guilty to charges of animal cruelty.

Shannon Walters, 34, of Newmarket is charged with animal cruelty in the death of Dewey, a miniature dachshund owned by her friend’s former boyfriend. She was arraigned Wednesday in York County Superior Court in Alfred, Maine.

Walters’ co-defendant, Erin M. Wylie, 27, of Portsmouth, pleaded not guilty on Oct. 28. Wylie was indicted last summer by a York County grand jury on counts of burglary, conspiracy and theft.

The women are accused of putting a wool sock over the dog’s head and carrying it to Wylie’s apartment in a garment bag. Both were indicted in New Hampshire and Maine but waived their right to arraignment in New Hampshire.

Wylie’s case will go to trial at Rockingham County Superior Court in Brentwood on Feb. 28. Walters’ trial is scheduled for March 14, according to the county attorney’s office.

A Portsmouth District Court judge found probable cause in Walters’ New Hampshire case in July after prosecutors argued that putting a sock over the dog’s face, stuffing it in a bag and later drowning it constituted torture.

Portsmouth lawyer Phil Desfosses argued during a hearing that if Walters held the dog underwater, it was to end the dog’s suffering.

Desfosses based his argument on the police testimony that indicated the dog was already in “poor condition” before the drowning.

The dog, along with some electronic equipment, had been taken from Wylie’s ex-boyfriend’s apartment in what was staged as a burglary.

Police have said Walters had a limited role during the break-in, serving primarily as “lookout” and watching Wylie collect various items, including the dog.