I speak as someone who has received over 3000 death threats. Why would someone who actually intended to kill you register their phone number to be investigated as a potential culprit? Why would they warn you they were coming? More worrisome are anti-abortionist style terrorists who broadcast your address and schedule and encourage other whackos to bump you off, like Lowell Green.
~ Roedy (born: 1948-02-04 age: 64)