Los Angeles (AFP) – Porn star Ron Jeremy is not mentally competent to stand trial, a judge has ruled, halting attempts to prosecute him for a dozen rapes and other alleged sex crimes. Tuesday’s ruling came almost a year after Jeremy was ordered to undergo psychiatric exams after his attorney suggested the adult film performer was struggling to recognize him. Jeremy, who has appeared in more than 1,700 X-rated films since the 1970s, had denied a raft of sex charges against women and girls between the ages of 15 and 51. The allegations cover a period of 23 years, dating back to 1996. Mental comp…