Can a thief reset my iPhone to get past Lost Mode?

My iPhone 5 has been stolen. I remotely locked it using Find My iPhone app, but now the phone is no longer transmitting a location, leading me to suspect he may have just reset my phone - but is this possible?

Prepare to live forever.

They can put the phone in DFU mode then reset it. You could report the iphone stolen and give the serial # so you might be able recover it.

If you deactivated it, the SIM won't work. When he tries to get a new SIM and activate it, they will check the IMEI number and find out it's stolen (assuming you reported it). I bought my wife a used 4 off someone at work. When I went to get it activated that's what they told me.

Same thing happened to me.
First off, be sure to call your carrier and tell them your phone was stolen so that the person who stole your phone can't use it.
The second thing you need to do is file a police report with your local police depo and give them your phone's serial number. This way if the thief tries to take it to a pawn shop or another carrier, the police depo. Will know. Stay on top of the detective that handles your case because they are busy people. The iphone 5's retail price starts at 650 so that is a MISDEMEANOR.
It might also be a good idea to keep an eye out on craigslist, and see if anyone post an ad for a phone, the same model as yours. A dead give away is when they are not offering to sell the charger or if it does not come in it's original box.
Where was your phone stolen? There may have been security footage. Or do you already know the thief?
My iphone 5 was stolen 2 weeks ago, just like yours. The police have the name, address, and phone number of the thief because she was caught on camera and left a paper trail but she refuses to hand over my phone.

How to bypass lost mode on iphone 7 plus

If you ve given up on getting your iPhone or iPad back, you can and should remotely erase it. Even if it s offline, it will be erased the next time it comes online. GrayKey could allow police departments and other government agencies to bypass your passcode, but Apple is fixing this with USB Restricted Mode.