Aurora, Colorado (CNN) -- A notebook allegedly mailed to a psychiatrist by movie-theater shooting suspect James Holmes before the July attack will remain off-limits to prosecutors, but defense lawyers will get to look at it under an agreement reached Thursday.
During a court hearing, prosecutors added 10 new attempted murder charges and amended 17 others among the 142 already lodged. Holmes appeared in court with close-cropped dark hair instead of the bright orange hair he had shortly after his arrest.
Holmes is accused of murder, attempted murder, weapons violations and other charges.
Prosecutors and defense attorneys waived a reading of the new and amended charges, but court officials later posted them online.
Holmes is accused of killing 12 people and wounding 58 during a midnight screening of the Batman film "The Dark Knight Rises" July 20 at an Aurora cinema.
Officials in the case are under a gag order issued by Judge William Sylvester to protect Holmes' rights.
Prosecutors had sought to review the notebook, received by University of Colorado psychiatrist Lynne Fenton, saying that it could shed light on the attacks. Defense lawyers objected, saying the document is a confidential communication between patient and doctor.
Prosecutors still dispute that argument, Deputy District Attorney Rich Orman said Thursday. But he said arguing the point now would result in a lengthy delay that prosecutors would like to avoid.
Under a proposal made by Orman, prosecutors will drop their efforts to see the document and will allow defense attorneys access to the as-yet unopened notebook under the watchful eye of a police officer.
Attorneys will have to wear gloves and masks, and other precautions will be taken to prevent the loss of evidence should the notebook later become evidence in the case, according to the agreement.
Should Holmes' legal team raise the issue of their client's mental health at any point during the trial, the notebook will become automatically available to prosecutors as potential evidence, Orman said.
Fenton has previously testified that her contact with Holmes ended more than a month before the shooting and that she had contacted campus police because she was concerned about what had happened during their last meeting.
Meanwhile, city work crews dismantled makeshift memorials to victims Thursday.
The toys, notes and other materials were boxed and labeled under the supervision of the Aurora History Museum for storage, the city said, and they'll remain available to family members to view at a secure location.
Aurora officials also plan to give family members white crosses that had stood at the memorial site, or store them at the discretion of relatives. Flowers and other perishable items were taken to a city park to be used as mulch, according to the city.
Authorities have not provided any motive for the shooting.
Holmes, a former doctoral candidate in neuroscience at the University of Colorado Anschutz Medical Campus in Aurora, failed his graduate school oral boards a month before the shooting.
Soon after, he was "denied access to the school after June 12, 2012, after he made threats to a professor," according to court documents.
Holmes then "started the process to voluntarily withdraw from his graduate studies program," the documents said.
The shooting unfolded inside a darkened theater packed with Batman fans, some in costume, for the premiere of the movie.
The suspect went to the rear door of Century 16 theater and propped it open, then tossed in a canister of irritant before unleashing a hail of gunfire, federal authorities said. Along with the gas mask, the suspect wore a ballistic helmet, protective gear for his legs, throat and groin, and black gloves.
Police officers rushing to the theater encountered bloody victims streaming out as others remained inside suffering from gruesome injuries.
Holmes surrendered without resistance, and authorities quickly learned that the suspect's Aurora apartment had been rigged with explosive booby traps.
Authorities evacuated five buildings in the neighborhood, and it took days to disarm all the makeshift bombs left inside Holmes' apartment.
In an initial interview with police, Holmes identified himself as "the Joker," authorities said.
CNN's Calandra Corder contributed to this report.