In a tweet late Tuesday, President Trump criticized Apple for refusing “to unlock phones used by killers, drug dealers and other violent criminal elements.” Trump was specifically referring to a locked iPhone that belonged to a Saudi airman who killed three U.S sailors in an attack on a Florida base in December.

It’s only the latest example of the government trying to gain access to a terror suspect’s device it claims it can’t access because of the encryption that scrambles the device’s data without the owner’s passcode.

The government spent the past week bartering for Apple’s help. Apple said it had given to investigators “gigabytes of information,” including “iCloud backups, account information and transactional data for multiple accounts.” In every instance it received a legal demand, Apple said it “responded with all of the information” it had. But U.S. Attorney General William Barr accused Apple of not giving investigators “any substantive assistance” in unlocking the phone.