Jodi Arias Trial Update: Jury foreman says convicted killer "was not a good witness" Jodi Arias reacts May 8 after she was found of guilty of first-degree murder in the 2008 killing her one-time boyfriend, Travis Alexander, in his suburban Phoenix home. (CBS/AP) - William Zervakos, the foreman of the jury that on Thursday said they couldn't decide whether convicted killer Jodi Arias should be sentenced to death, has said that Arias' 18 days on the witness stand during her murder trial didn't do her any good. "I think 18 days hurt her," Zervakos told Good Morning America Friday. I think she was not a good witness. Zervakos said with the prosecutor's aggressive style, that length of time testifying "would be difficult for anybody. I don't think I'd want to sit on the stand for 18 days. The same jury convicted Arias of first-degree murder in the 2008 stabbing death of her lover Travis Alexander. Judge Sherry Stephens gave a sigh as she announced a mistrial in the penalty phase of the case after the jury's announcement, and Alexander's family sobbed. Arias looked stunned and put a hand to her cheek with a half-smile. The foreman told the show he had a difficult time believing Arias would be capable of slashing and stabbing Alexander about 30 times. "When I walked into the courtroom for the first time and looked at who the defendant was, you know it's hard to put that in perspective," Zervakos said. When you look at the young woman and think of the crime, and then you see the brutality of the crime, it just doesn't wash - it's very difficult to divest yourself from the personal, from the emotional part of it. He said he didn't believe Arias' story of self defense, but that he did believe Alexander "mentally and verbally" abused Arias. Is that an excuse? Does it factor in the decision that we make? It has to," he said. Listening to the emotional victim impact statements from the family of Travis Alexander was difficult, he said. "Until you're face to face with people that have gone through something like that, it's something you can't put it into words," he told Good Morning America. I'm six feet away from somebody who is talking about a horrendous loss. If you can't feel that you have no emotion, no soul. And yet we couldn't allow ourselves to be emotional on the stand...it was a gut-wrenching thing we had to go through, and everyone had to make their own decision. The jury didn't speak to reporters immediately following the announcement, AZcentral.com reported. As the jury filed out, three women on the panel cried and one looked to the victim's family, mouthing the word, "Sorry." The jury was split 8-4 in favor of death, azcentral.com reported. The mistrial set the stage for a whole new proceeding to determine whether the 32-year-old former waitress should get a life sentence or the death penalty for murdering Alexander five years ago. Prosecutors have the option to take the death penalty off the table, in which case a new trial wouldn't be necessary and the judge would determine whether to sentence Arias to spend her entire life behind bars or life with the possibility of release after 25 years. Should the state decide to seek death again, jury selection alone could take weeks, given the difficulty of seating an impartial panel in a case that has attracted global attention. The guilty verdict of first-degree murder would stand, leaving the new panel only tasked with sentencing Arias. However, former Maricopa County Attorney Rick Romley said the case could drag on for several months as the new jury reviews evidence and hears opening statements, closing arguments and witness testimony in a "Cliffs Notes" version of the trial. If the second jury cannot reach a unanimous decision, the judge would then sentence Arias to one of the life-in-prison options.