US Attorney General William Barr called on Apple to help police access two iPhones used by a man accused of killing three people on a naval base in Florida in December 2019, noting the company had thus far failed to assist the investigation.

Barr told press the situation “perfectly illustrates why it is critical that investigators be able to get access to digital evidence once they have obtained a court order based on probable cause” and urged technology companies “to help us find a solution so that we can better protect the lives of Americans and prevent future attacks”.

Investigators secured a court order authorising a search of both devices to determine who the accused may have been communicating with prior to the attack. However, Barr noted the phones are “virtually impossible to unlock” without a password.

Though the Department of Justice (DoJ) asked Apple for its help accessing the phones, Barr said the company failed to provide “substantive assistance”. Barr declined to comment on whether the DoJ planned to sue the tech giant to force it to help.

Barr commented as politicians and police continue to wrangle with technology companies over whether so-called back door channels should be built into devices to provide easier access in certain circumstances. Tech companies argue this would negatively impact user privacy and security.

Apple found itself in a standoff with the Federal Bureau of Investigation under similar circumstances in 2016, before a third-party company was able to successfully access data on an iPhone used by one of the shooters in a 2015 mass killing in California.