Forensic psychiatry uses the legal aspect of psychiatry to aid in court cases. Expert psychiatric testimony influences legal verdicts and judgments. A forensic psychiatrist evaluates individuals involved in court cases, plays an important part in custody suits, and provides treatment to incarcerated patients. He or she can determine competency in criminal cases, in legal business procedures (such as contracts or investments), and give assistance in harassment and discrimination cases.

Doctor density varies by specialty and location. The United States has 1,204 practicing forensic psychiatrists. Broken out by state, forensic psychiatry doctor density in Alabama is 6, in Arizona is 21, in Arkansas is 6, in California is 213, in Colorado is 24, in Connecticut is 22, in Delaware is 3, in District of Columbia is 18, in Florida is 70, in Georgia is 26, in Hawaii is 7, in Idaho is 2, in Illinois is 50, in Indiana is 10, in Iowa is 8, in Kansas is 6, in Kentucky is 14, in Louisiana is 33, in Maine is 4, in Maryland is 40, in Massachusetts is 77, in Michigan is 39, in Minnesota is 14, in Mississippi is 8, in Missouri is 28, in Montana is 2, in Nebraska is 10, in Nevada is 9, in New Hampshire is 6, in New Jersey is 47, in New Mexico is 8, in New York is 153, in North Carolina is 33, in North Dakota is 1, in Ohio is 55, in Oklahoma is 1, in Oregon is 19, in Pennsylvania is 45, in Rhode Island is 9, in South Carolina is 27, in Tennessee is 15, in Texas is 76, in Utah is 7, in Vermont is 5, in Virginia is 37, in Washington is 21, in West Virginia is 7, in Wisconsin is 18, and in Wyoming is 3.