Prosecutors said today they have opened a criminal investigation into a fatal California balcony collapse that could lead to involuntary manslaughter charges.
However, Alameda County District Attorney Nancy O'Malley declined to discuss any possible target of her investigation, saying it could end with no charges being filed.
"We will ultimately have to make a determination whether the facts support criminal charges and whether those facts can be proven beyond reasonable doubt in a court of law," Ms O'Malley said during a packed news conference at her Oakland office.
Six students were killed last week and seven others were injured when a balcony broke from the side of a Berkeley apartment building.
Olivia Burke, Eoghan Culligan, Niccolai Schuster, Lorcan Miller and Eimear Walsh, all 21-year-olds from Ireland, and Ashley Donohoe, 22, of Rohnert Park, California, were killed on June 16 when the balcony fell during a birthday party.
Ms O'Malley announced the criminal investigation two days after city inspectors said the balcony was supported by wooden beams that had been badly rotted by water damage. City officials said at that time they would investigate no further.
City of Berkeley spokesman Matthai Chakko declined to comment further today, citing the criminal investigation.
Ms O'Malley said law enforcement officials have secured the fallen, fifth-storey balcony for examination by forensic experts.
Another balcony one storey below the fallen one was removed from the apartment building and is also being held by law enforcement officials as part of the criminal probe, she said.
Ms O'Malley said prosecutors would have to show criminal negligence was involved in the collapse in order to file charges and gain convictions.
"It is possible that we will conclude that the facts will not support a criminal prosecution," she said.
Trevor Martin, a spokesman for Segue Construction, the contractor in charge of building the Berkeley apartment complex, did not immediately return phone or email inquiries today.
The company recently settled two lawsuits involving balconies with dry rot at two apartment buildings in California for a combined 6.5 million US dollars (£4.1 million).
Lawyers say it is difficult to win convictions against property owners, contractors and others involving allegations of construction failures.
The last-known criminal prosecution of a balcony collapse in California occurred in San Francisco almost 20 years ago.
A prosecutor charged a property owner with involuntary manslaughter and other counts related to the 1996 fatal collapse of a balcony in the city's Pacific Heights neighbourhood. That collapse killed one person and injured 14 others.
A jury deadlocked on the manslaughter charge, which prosecutors dismissed.
The landlord was convicted of two misdemeanours and paid 13.5 million US dollars (£8.5 million) to settle lawsuits, according to lawyer Niall McCarthy, who represented one of the people hurt.