James Martin/CNET

The US government still needs Apple's help to break into an iPhone. And this time, it's not about terrorism.

The Department of Justice on Friday told a federal court in New York that it will appeal a ruling from late February that Apple didn't have to help unlock an iPhone 5S used by a drug dealer. The man involved in the case confessed his crimes and will be sentenced in May.

"The government continues to require Apple's assistance in accessing the data that it is authorized to search by warrant," the agency said in a court filing.

An Apple attorney, speaking with reporters Friday on the condition of anonymity, expressed disappointment that the government decided to pursue the case in New York but said Apple isn't surprised. The attorney reiterated Apple's stance that the government is trying to set a precedent in forcing Apple to help law enforcement unlock iPhones.

Apple will file its response to the brief on Thursday, and then there will be a hearing set on the issue.

The New York case is one of a number in which the government has looked to Apple to help bypass security on iPhones. The most notable involved an iPhone 5C tied to the San Bernardino, California, terrorist attack in December. In that case, after fierce resistance by Apple, the government ended up getting a work-around from a third party. The work-around applies only to the 5C and not to later models of the iPhone. The FBI still hasn't told Apple how it got into the phone.

In both instances, the US has invoked the two-century-old All Writs Act to compel Apple to help. A New York judge had determined the act couldn't be used to force Apple's hand, something the DOJ wants reversed. It's up to individual courts around the country to determine whether Apple should help or not.

There are dozens of iPhones law enforcement agencies want unlocked, including the iPhone 6 Plus of an alleged member of Boston's Columbia Point Dawg gang. A judge in February ordered Apple to help the FBI, according to documents unsealed Friday.

An Apple attorney said Friday that Apple will use the case in New York to determine what steps the FBI has taken to get into the phone. To be able to use the All Writs Act, the government has to show that Apple's help is essential in getting information off the device and that doing so won't be an undue burden to Apple.

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The New York and California cases have some notable differences. In the New York case, the phone is a higher-end iPhone than the device used in San Bernardino -- a 5S versus a 5C. The 5S has a fingerprint reader, which provides tougher security. But the phone is running iOS 7 compared with iOS 9 in San Bernardino. The two-year-old software has less-stringent security controls, which should make it easier to get data off the phone.

And in the New York case, the FBI wants Apple to extract data from the iPhone 5S, not help determine the passcode, like in California. Apple would have had to create new software to bypass its own device security for the iPhone used by the San Bernardino terrorist. The company argued that doing so would be an undue burden and put all iPhone users at risk. In New York, it wouldn't have to create entirely new software to get information off the device.

The California case turned the previously private dealings between Apple and the FBI into a public battle and started a broader debate over privacy and security. Technology companies and rights groups argue that strong encryption, which scrambles data so it can be read only by the right person, is needed to keep people safe and protect privacy. Law enforcement argues it can't fight crimes unless it has access to information on mobile devices.

Late Thursday a draft was released of a Senate Intelligence Committee bill that would require companies to help investigators access encrypted information, either by providing the data themselves or providing "technical assistance," according to The Hill. Apple didn't have a comment about the legislation.

Update, 10:20 a.m. PT: Adds comments from Apple and background.

Update, 4:45 p.m. PT: Adds information about Boston case.

DOJ letter to court in New York needing Apple's help