FEATURE-Colorado rule lets massacre trial jurors dig into thorny issues

CENTENNIAL, Colo., May 12 (Reuters) - Lobbing questions on topics ranging from loading ammo clips to booby-trapping apartments and the chemistry of gunshot residue, jurors have waded into the thick of the Colorado movie massacre trial as they weigh the fate of gunman James Holmes.

Taking full advantage of unusual state rules that require the judge to let them question witnesses, the jury of 19 women and five men have asked probing follow-ups on issues including crime scene forensics and Holmes' behavior before the rampage. They have also made more unexpected contributions.

Admonished by Arapahoe County District Court Judge Carlos Samour several times a day not to discuss the case with each other or anyone else, inside Courtroom 201 they have taken to their role with energy.

The jurors will first decide if Holmes is guilty of killing 12 people and wounding 70 more, and then whether he is to be executed. At the trial, they pass written questions to Samour, who reviews and reads them to witnesses.

Colorado is one of only three U.S. states, along with Arizona and Indiana, where jurors have a mandated right to question witnesses in both criminal and civil trials. It is much rarer in other states, where it is at the judge's discretion.

There are many signs the jurors are seriously heeding Samour's instructions about their importance in the life-or-death process.

Following testimony from Colorado Bureau of Investigation forensic analyst Carol Crowe about gunshot residue, several submitted questions asking how long the chemicals remain on objects.

Addressing Crowe, public defender Daniel King noted that attorneys from both sides had neglected that obvious question during their direct and cross examinations.

"You know, ma'am, when four jurors ask the same question, it may be a teaching moment for the lawyers," King said.

Jurors have also asked expert witnesses whether ammunition clips come pre-loaded; if not, how long they take to load, and how long it would take an FBI special agent to set up the bombs Holmes used to booby-trap his apartment.

They also asked whether the devices at the apartment appeared intended to harm, or just to intimidate.

'GLIMPSE INTO THINKING'

Holmes, 27, has pleaded not guilty by reason of insanity to multiple counts of murder, attempted murder and explosives charges. Prosecutors have said they will seek the death penalty for the Southern California native if he is convicted.

Longtime Colorado criminal defense lawyer Mark Johnson said that when the state began allowing jurors to question witnesses in 2004, he opposed the policy. But he said the insight it gives lawyers won him over.

"You can really get a sense of the issues jurors are considering by getting a glimpse into their thinking," Johnson said.

Some queries from the jury box have been more mundane. One juror said a model of the theater in the center of the courtroom blocked their view of Holmes, and they wanted it moved to see his demeanor during testimony.

Neither side's lawyers objected, so the mock-up was carried away.

Two jurors told the judge separately that they personally knew survivors who gave harrowing testimony about the massacre.

One juror said he did business with a witness. The other juror said a victim's son goes to the school where she works. Both were allowed to remain on the panel after telling the judge the relationships would not affect their impartiality.

Twelve of the jurors are alternates and will only have to deliberate if others drop out. But only Samour and the lawyers know who they are, and all 24 have been told they must pay close attention.

One juror wrote to the judge suggesting a fix to make life easier for witnesses, who have to leave the stand and use a hand-held microphone and makeshift pointer when asked to indicate parts of images shown on a large courtroom television.

Samour read the note aloud, which proposed attaching a second mouse to a computer on the stand and enlarging the pointer on the screen, allowing the witness to stay seated while testifying.

"It's a good suggestion; I thought about it, your honor, but I thought it was too complicated for us to handle," prosecutor Rich Orman told the judge, to laughter from the court.

Samour drew more chuckles when he replied: "We're going to build a suggestion box."

(Reporting by Keith Coffman and Daniel Wallis; Editing by David Gregorio)