WATSONVILLE, Calif. -- A 3-year-old girl found dead in a Watsonville motel room Sunday afternoon was identified Tuesday as Isabella Grace Martinez, police Lt. Darren Thompson said.

Isabella's mother was arrested and booked into Santa Cruz County Jail on suspicion of murder, Thompson.

Officers were called to the Motel 6 at 125 Silver Leaf Drive around 2 p.m. after housecleaning staff reported finding Isabella's body.

Police learned the mother, Aptos resident Veva Virgil, 37, checked into the motel room Saturday and left Sunday morning, Thompson said.

"She left and it didn't appear she had any intention of returning," he said.

Virgil was contacted and allegedly confessed to "acting alone to kill the child in a motel room at Motel 6," Thompson said.

"She was living in Aptos with her husband and she came down and rented the room and stayed at least one night," Thompson said. "She left the next day and left the child deceased in the room."

Thompson said Virgil's husband is the 3-year-old girl's stepfather.

While Virgil allegedly told police she acted alone, detectives have continued to investigate whether another person was present at the time of Isabella's death, Thompson said.

A preliminary investigation has indicated Isabella died of strangulation, but Thompson said the investigation is ongoing.

The murder is the city's third of the year, with two gang-related homicides reported in October, Thompson said.

Anyone with information about the case is asked to contact police at (831) 768-3350 or the Crime Tip Line at (831) 728-3544.