DENVER - On Tuesday, Aurora theater shooting suspect James Holmes pleaded not guilty by reason on insanity.
The insanity defense is used in approximately 1 percent of the time in all court cases, according to the Colorado Department of Human Services.
Persons adjudicated as not guilty by reason of insanity (NGRI) in Colorado are committed to the Colorado Department of Human Services to receive in-patient forensic care and treatment at the Colorado Mental Health Institute-Pueblo (CMHIP).
CMHIP has 451 beds. The state says 144 beds are used by people in the community who have acute mental illness, substance abuse issues and those with serious psychiatric disorders.
The other 307 beds are used for people referred by the criminal justice system. Evaluation and treatment services are provided to adults pre-trial, post-conviction or following acquittal by reason of insanity.
Of the 307 criminal justice beds, 124 are occupied by people who have been found not guilty by reason of insanity and 138 are occupied by people found incompetent to proceed, according to state officials.
-- Juries don't always agree --
Jurors do not always accept a not guilty by reason of insanity plea. In March, Bret Lee Luckett Thompson claimed he was insane, but jurors decided he was not, and found him guilty of kidnapping and sexually assaulting an 8-year old girl.
In February, another jury found Edward Romero guilty of shooting, killing and dismembering a 16-year old neighborhood girl. He had pleaded not guilty by reason of insanity.
-- Other killers have been found insane --
The man who shot two eighth graders outside Deer Creek Middle School in Jefferson County in 2010 was found not guilty by reason of insanity. After deliberating less than two days, jurors found Bruco Strong Eagle Eastwood not guilty by reason of insanity on two counts of attempted murder, two counts of first-degree assault and two counts of child abuse. However, the jury found him guilty of possession of a weapon on school grounds.
He will serve that sentence only if state psychologists deem him healthy enough to leave the state mental hospital.
In 2012, a judge found a Superior mother, Stephanie Rochester, not guilty by reason of insanity in the 2010 death of her 6-month-old son. A psychiatrist testified that Rochester suffered from major depression with psychotic symptoms and saw her son as an "alien, toxic, contaminated being."
However, Rochester's husband, Lloyd Rochester, said he was "disappointed" the case hadn't gone to a jury, and the family was never convinced Stephanie Rochester wasn't malingering or making up her psychotic symptoms.
-- Insane people may get out of the hospital --
Many of the people sent to the state mental hospital face the possibility of being released or being granted supervised outings.
Last year, a man found not guilty by reason of insanity in the slayings of four people in Rifle in 2001 was granted supervised outings. A judge ruled that Steven Michael Stagner should be allowed to go hiking and attend movies as part of his treatment. Stagner has been at the Colorado Mental Health Institute at Pueblo since he was found not guilty by reason of insanity in 2002.
However, because Stagner targeted Latinos, as part of the conditions of the outings, Stagner will not be allowed in areas where there are a large number of Latinos.
-- Making insanity pleas tougher --
Earlier this year, state lawmakers debated Colorado's insanity statues. Lawmakers reviewed a proposal to make it tougher for Colorado defendants to be found not guilty by reason of insanity by putting the burden of proof on defense attorneys, instead of prosecutors.
At least 30 states put the burden of proof for such claims on defendants, but not Colorado. Colorado's Supreme Court ruled in 1968 that putting the burden on defendants is unconstitutional.
A House committee in February voted against the bill, killing it.