Police say they are suspending their investigation into the Christmas Day tiger attack at San Francisco Zoo that left a teenager dead.

The San Francisco Police Department released a statement Tuesday saying the investigation has been put on hold "pending new witnesses being interviewed and/or new evidence being produced."

In court documents filed earlier this month, police investigators said they believed the attack was in part triggered by the victims provoking the animal but did not specify what if any crimes they thought had been committed.

The escaped 250-pound Siberian tiger fatally mauled 17-year-old Carlos Sousa Jr. and wounded his friends, brothers Paul and Kulbir Dhaliwal, after apparently climbing or leaping from its enclosure.