* Lawyers for the accused appear to be building insanity defense
* Defense has highlighted bizarre behavior of client
By Keith Coffman
CENTENNIAL, Colo., Jan 9 (Reuters) - Prosecutors were expected to finish presenting their case to a Colorado judge on Wednesday in the preliminary hearing of a former graduate student charged with shooting 12 people to death and wounding 58 others in a movie theater last summer.
The proceedings will then be turned over to lawyers for accused gunman James Holmes, who went out of their way in cross-examination of witnesses this week to highlight strange behavior exhibited by their client before and after his arrest.
Should Arapahoe County District Judge William Sylvester order the case to proceed to trial, legal experts believe Holmes will plead not guilty by reason of insanity.
His lawyers have said he suffers from an unspecified mental illness and are expected to call two witnesses later this week to testify about his state of mind around the time of the massacre, which ranks among the deadliest mass shootings in U.S. history.
Homicide detective Craig Appel acknowledged under defense cross-examination that Holmes tried to insert a staple he found on a desktop into an electrical outlet during an initial interrogation at police headquarters.
During that interview, in which Holmes had plastic bags placed over his hands to preserve any traces of gunpowder residue, Holmes also gestured with one of the bags as if it were a talking hand puppet, Appel testified.
Asked why blood samples were not taken of Holmes following his arrest, even though police officers noted that his pupils appeared to be extremely dilated, Appel added, "I saw no indication that he was under the influence of anything."
The former University of Colorado neuroscience doctoral student is charged with multiple counts of first-degree murder and attempted murder stemming from the July 20 rampage at a midnight screening of the Batman film "The Dark Knight Rises" in the Denver suburb of Aurora.
The first three days of the preliminary hearing focused on evidence presented by prosecutors seeking to convince the judge they have sufficient evidence to put Holmes, 25, on trial. Prosecutors have yet to decide whether to seek the death penalty.
For the public, the hearing has laid bare many details authorities have refused to divulge, or were prohibited from disclosing under a strict gag order imposed by the judge.
Police testified that Holmes, who bought his movie ticket 12 days in advance, left the screening minutes after it began and re-entered Theater 9 at the Century 16 multiplex a short time later dressed in tactical body armor, a gas mask and helmet.
Armed with a semi-automatic rifle, shotgun and pistol, police say, he then lobbed a tear gas canister into the auditorium and sprayed the audience with bullets.
Later, in the parking lot, he surrendered without a struggle to the first police officers arriving on the scene and alerted them that his apartment had been booby-trapped with explosives.
Police also described encountering a nightmarish, bloody scene inside the darkened theater, where dozens of victims lay sprawled across the auditorium as the Batman film continued to play and emergency-alarm strobe lights flashed.
On Tuesday, a detective played recordings of two emergency 911 calls received by authorities from inside the theater during and just after the shooting. A burst of 30 gunshots was audible in one 27-second tape.
In another, a 13-year-old girl caught in the shooting with her 6-year-old cousin, Veronica Moser-Sullivan - the youngest person to die - and Veronica's pregnant mother, Ashley Moser, who was badly wounded, was heard frantically pleading for help.