BOISE - Federal prosecutors and Joseph Duncan have come to an agreement that will likely keep Shasta Groene off the witness stand.

It's been determined that the court will use taped interviews and transcripts given by Shasta following her 2005 rescue where she witnessed her brother Dylan being shot to death.

On Thursday, Shasta's father, Steve Groene, took the stand for several minutes. He was in court on Thursday - mostly to identify photos of Dylan and Shasta who was 8 at the time in May 2005.

Most of the morning's testimony came from law enforcement including Kootenai County and Idaho State Police officers who responded to the house near Couer d'Alene, where the bodies of Brenda Groene her son Slade and fiancé Mark Mackenzie were found.

On Wednesday U.S. attorney Tom Moss graphically described how Duncan crept into the house, tied everyone up, then beat the three to death with a hammer before abducting Shasta and Dylan.

One officer testified that the scene was so grisly he actually quit law enforcement for a time because "this case pushed me to the end."

Duncan gave a brief statement on Wednesday saying he intends to take the stand and answer questions jurors may have. The death sentencing hearing is expected to last up to six weeks.

The jurors will decide whether Duncan should spend life in prison without parole or get the death penalty in connection with the 2005 kidnapping of Shasta and Dylan Groene in northern Idaho and the murder of Dylan.

Duncan plead guilty to the crimes in December.

But it will not be easy on the jurors. Judge Edward Lodge has warned jurors they'll have to review disturbing videotape made by Duncan as he tortured and abused Dylan.

As father Steven Groene testified, the letters from 9-year-old Dylan and 8-year-old Shasta were only flashed on a screen briefly, and prosecutors avoided discussing the contents.

But they're likely to be the letters found in the car Duncan was driving just before he was arrested with Shasta in a Coeur d'Alene restaurant. Excerpts suggest Duncan directed the children to write them.

"Dear dad, I miss you very much. Me and Dylan know what happened," to their slain family members, one letter from Shasta read.

"I'm sorry you had to lose a son and an ex-wife and I'm sorry we were taken from you ... We are still alive and we are ok," read another.

The final letter, which Steven Groene said he'd never seen before, offered a false promise.

"I have good news we will be home soon," the letter read, "maybe in a week or 2."

After testifying about the identities of his children and confirming their handwriting, Groene stepped down, visibly choked up by the evidence.

(The Associated Press contributed to this report.)