The man accused of killing former Navy SEAL Chris Kyle and another man has not been indicted within 90 days as Texas law requires.
Eddie Routh, a former Marine, was arrested in the slayings of Kyle and Chad Littlefield more than three months ago.
The timing is key, because Texas law says defendants are entitled to a speedy trial and could be released from jail on reduced bond or no bond if they are not formally charged within 90 days.
Attorneys for Routh have not asked for his release. He remains in the Erath County Jail on a $3 million bond.
A spokeswoman for Erath County District Attorney Alan Nash said investigators have not presented the case for prosecution.
Erath County Sheriff Tommy Bryant said the Texas Rangers took over the investigation soon after the shootings at a gun range near Glen Rose.
Asked by NBC 5 about the delay, the Rangers said in a statement that, "There are many parts to this active investigation, and it may take some time before the investigation is completed and ready to present to the district attorney. No additional information will be released at this time."
Routh's attorney, J. Warren St. John, of Fort Worth, declined to comment.
The Feb. 2 shootings were national news.
The memorial service for war hero Kyle was so big that it was held at Cowboys Stadium. His funeral procession to Austin drew thousands.
The case against Routh, who reportedly had been seeking treatment for post-combat stress, seemed strong. He confessed to his sister, police said. He was arrested driving Kyle's pickup after a chase in Lancaster.
In jail, Routh has refused to see most visitors, including his parents, and has stopped taking his medication, Bryant said.
Routh also has declined to leave his small cell, where he is held in solitary confinement, for exercise, the sheriff said.
"He reads and watches television and sleeps a lot," Bryant said.
Routh had sought treatment at the Veterans Administration for his stress, and friends said Kyle was trying to counsel him when Routh turned on him.
His mental health is expected to be a key issue in his case.