On devices running Android 5.0 to 5.1.1, the password lock screen (not the pin or pattern locks) can be bypassed by crashing the screen UI. This can be accomplished by following these steps, as explained at: https://android.gadgethacks.com/:

1. Click on the Emergency Call option on the lock screen and then enter any random input (for example, 10 asterisks) on the dialer screen.
2. Double-tap the field to highlight the entered text, as shown in the following screenshot, and choose Copy. Now, paste it into the same field:

3. Repeat this process of copying and pasting to add more characters until double- tapping the field no longer highlights the characters.
4. Go back to the lock screen and open the camera shortcut. Now, pull down the notifications screen and tap the Settings icon. You will then be prompted to enter a password.
5. Long-press the input field and choose Paste and repeat this process several more times. After pasting enough characters into the field, the lock screen will crash and allow you to access the device.