* Former student charged with killing 12 during Batman film
* Prosecutors outline evidence against accused gunman
* Officer follows trail of blood to suspect who surrendered peacefully (Recasting top of story; adds details from early testimony)
By Keith Coffman
CENTENNIAL, Colo. Jan 7 (Reuters) - James Holmes heard a policeman describe in court on Monday following a trail of blood to a suburban Denver movie theater, finding a man in full body armor wearing a gas mask and helmet and ordering the former graduate student to freeze and surrender.
Holmes, 25, accused of fatally shooting a dozen people in a Colorado cinema in July, "immediately put his hands up" and "seemed very detached from it all," said Officer Jason Oviatt, the first witness called by prosecutors in a hearing about the killings.
Oviatt said the suspect offered no resistance as he was handcuffed and taken into custody.
A second officer, Aaron Blue, recalled arriving on the scene to find "a lot of people coming out of the theater screaming," and testified about how he and his partner transported one woman to the hospital as he sat in the back seat cradling her wounded head. She later died.
The officers' testimony made a dramatic start to lengthy proceedings in which prosecutors are seeking to convince a judge they have enough evidence to put Holmes on trial.
The one-time University of Colorado doctoral student of neuroscience is charged with multiple counts of first-degree murder and attempted murder stemming from a rampage that killed 12 people and wounded 58 others during a midnight screening of the new "Batman" film, "The Dark Knight Rises" in Aurora, Colorado.
The preliminary hearing in the case is expected to last a week and offer the public its first detailed account of the investigation into one of the most chilling and deadly mass shootings in U.S. history.
NO REACTION TO TESTIMONY
Holmes, shackled and wearing a crimson jumpsuit, sat impassively at the defense table, showing no visible emotion or reaction to the testimony.
Gone was the dyed red hair that the California native sported when he was taken into custody. His natural dark brown hair has since grown back, and he appeared in court as he has in recent weeks with a full beard.
Most of the evidence against Holmes has been placed under seal, and Arapahoe County District Judge William Sylvester has issued a gag order preventing all parties, including law enforcement, from discussing the case outside of court.
Once the preliminary hearing ends, Sylvester will decide if there is sufficient cause for the case to proceed. If a trial is ordered, prosecutors would then have 60 days from the time Holmes enters a plea to decide whether to seek the death penalty in the event he is convicted.
Legal analysts assume that Holmes will ultimately plead not guilty by reason of insanity, based on statements from his defense attorneys and in court filings.
Public defender Daniel King has said his client suffers from an unspecified mental illness. And King has subpoenaed two witnesses for this week's hearing to testify about Holmes' mental state before the massacre, according to court documents.
The Aurora multiplex shooting ranked as the bloodiest instance of U.S. gun violence in 2012 until last month's massacre of 20 children and six adults at an elementary school in Newtown, Connecticut.
The circumstances of the movie killings stood out as particularly shocking. Authorities have said Holmes bought a ticket to the July 20 midnight screening and minutes into the movie left the theater, propping open an exit door.
He then donned protective ballistic gear and armed himself with numerous weapons, returned to the theater, lobbed a smoke canister into the crowd and opened fire, authorities said.
Officer Blue testified that just after Holmes surrendered, he blurted out that he also had booby-trapped his home with what Holmes called "improvised explosive devices."
Bomb squad technicians sent to the suspect's home managed to disarm homemade bombs without any detonating.
The Denver suburb was shaken by gun violence again on Saturday when a lone gunman holed up in an Aurora townhouse shot dead three people and was killed hours later by police. (Reporting by Keith Coffman; Writing by Steve Gorman; Editing by John Wallace, Grant McCool and Kenneth Barry)