NEW HAVEN, Conn. (AP) A former doctor charged with killing a Yale University physician says he disagrees with a judge's ruling that he's mentally incompetent to stand trial and objects to the possibility that he may be forced to take anti-psychotic medication to make him competent.

Lishan Wang is charged with murder in the shooting death of Dr. Vajinder Toor in 2010 outside Toor's Branford home.

Authorities say the shooting appeared to stem from a dispute Wang had with Toor and other doctors while they worked together at a New York City hospital that led to Wang's dismissal.

Wang was found incompetent to stand trial earlier this month.

Wang in a letter to The New Haven Register says he believes he is competent, and being forced to medicate ``will compromise my mental status'' at trial.