I used a digital rotary compression tester and on the rear rotor it tested 107/104/109 but on the front rotor it tested 20/20/20.. The previous owner swears up and down that the car ran and drove fine before he started taking the car apart.. I just find it odd that the front rotor tested so low with the same number for all 3 faces, any ideas on what I may need to double check to make sure the numbers are correct?

 

Sounds like you're using the rctv5.2. The lowest it reads is 20psi. If the compression number is lower than that then it will just show 20/20/20 like you're seeing. Spin the motor with the spark plugs out on the rear and the spark plugs in on the front. See if you can hear the compression pulses.

If you can then perform the test again and make sure the sensor is fully seated in the housing following the instructions on the box.

If the test shows the same result then the reading is accurate and in sorry for your loss