Tennessee Code Title 32. Wills § 32-4-105

(a) Upon the trial of the issue in case of a written will with witnesses, it shall be proved by all the living witnesses, if to be found, and by such other persons as may be produced to support it.

(b) Upon the contest of a holographic will, if the holographic will was written within thirty (30) days prior to a testator's death and the testator died by suicide, then there is a presumption of suspicious circumstances and the proponent of the will has the burden of presenting evidence demonstrating that the testator had the capacity to execute the will.