Utah Author Accused of Poisoning Husband Now Charged with Witness Tampering from Jail

Kouri Richins allegedly killed her husband by lacing his drink with fentanyl.
A letter found in Richins' jail cell detailed a plan for her brother to testify falsely about her husband's drug use.
Prosecutors say the letter proves Richins engaged in witness tampering.
Richins wrote a children's book about grief after her husband's death.
She faces charges of murder, witness tampering, and financial wrongdoing related to her husband's death.