Won't start - anti theft device?

Just bought a 96 Tacoma from a friend. It is in excellent shape. Went to start it today and some sort of anti-theft device is keeping the engine from turning over. There is a flashing red light at lower left below the fuse box. The beeper goes off and the emergency lights flash. My friend said he bought it from a guy that told him to press and hold the button at the back of the flashing device and turn the key. (Yes, I am pushing in the clutch pedal). After a while the lights and beeper go off but still no success.

I tried disconnecting the negative terminal of the battery (no success), removing a fuse under the hood (flashing light went off, but came back on after replacing fuse - no success)

Is this a Toyota option or 3rd party?
Any ideas on how to defeat this?

Thanks,
Greg