(Recasts, adds victim identity, details, byline)
By Jim Christie
SAN FRANCISCO, Dec 26 (Reuters) - San Francisco police on Wednesday investigated whether a Siberian tiger had help in escaping its zoo habitat before it killed a teenager and injured two other people on Christmas Day.
Police told a news conference at the San Francisco Zoo that they were treating the city-run facility as a crime scene. Investigators are looking into whether the tiger, which had mauled a zoo employee last year, had been taunted before its rampage.
Police also indicated they were considering whether someone might have let the 9-year-old tiger, known as Tatiana, out of its exhibit.
Police shot and killed the tiger after it turned toward them as they attempted to divert its attention from one of the injured victims on the ground.
Zoo spokeswoman Lora LaMarca said zoo officials could not comment on how the tiger got out of its habitat, a grotto surrounded by a 15-foot (4.5 meter) moat and 20-foot (6 meter) wall.
"It is an ongoing police investigation and it is still being looked into," LaMarca said.
San Francisco’s medical examiner identified the victim of the fatal attack as Carlos Sousa Jr., 17, of San Jose, California. He was pronounced dead at the scene.
The two other victims, 19- and 23-year-old brothers from San Jose, were reported in stable condition at a San Francisco hospital.
The tiger attacked Sousa in front of its enclosure and the the brothers about 300 yards from it.
The same tiger had injured a zoo worker during a public feeding last December. The zoo made safety upgrades and recently resumed the public feedings. (Reporting by Jim Christie; Editing by Bill Trott)