A panel of independent mental health practitioners will assess the suspect. Contrary to what you claim, a suspect can’t just appear in front of a judge and have their solicitor claim they have mental health issues.
It’s a rigorous process and is not taken lightly.
If they are found to be...
A crime gets committed, if enough evidence is produced the suspect gets charged, mitigating circumstances such as poor mental health are then considered.
Anyone who has looked even briefly at what that woman has achieved in her life wouldn’t have the brass neck to put DA down. A remarkable woman who made her way in 1970’s England as a black MP. Almost unheard of.