The Metropolitan police virus is a randomware package the disables use of the desktop while running Windows.
The way to remove this virus is to see if the computer will reboot into safe mode with networking.
If it does, simply run MBAM and wait until it's removed all found infections. Upon reboot the virus will be gone.
If you cannot access safe mode, the best thing to do is to remove the HDD from the infected machine and attach is as mass storage to another system.
After this, you simply run MBAM on the host system, performing a scan on the newly attached mass storage device (your infected HDD).