Two years ago, a controversial “brain-mapping” technology — allowed into evidence by one Miami-Dade judge — helped spare convicted Kendall murderer Grady Nelson from the death penalty.

But the prospect of widespread use of the technology in criminal court has dimmed as, one by one, Florida judges have refused to allow use of the “QEEG,” which some defense lawyers say explains a propensity for violence by illustrating brain trauma.

The latest South Florida case: a judge declined to allow defense lawyers to present the technology to jurors in a possible death penalty hearing for Dennis Escobar, accused of murdering a Miami cop in 1988.

Miami-Dade Circuit Judge Leon Firtel last month said the way defense experts interpret the brain-mapping technology was “not accepted” by the scientific community.

The decision — along with a similar ruling by another Miami-Dade judge, and one in Charlotte County on Jan. 2 — has vindicated prosecutors who have long maintained that the QEEG, or Quantitative Electroencephalogram, is unreliable.

“I’m hopeful that we can close the door on this chapter of junk science,” Miami-Dade State Katherine Fernández Rundle said. “It’s unnecessary spending of precious dollars needed elsewhere in the courts system.”

Terry Lenamon, who represents the accused Charlotte County killer, says he still believes the QEEG has a future in Florida criminal courts.

“We are at a time that science is moving forward in a way that is inconsistent with old, traditional methods,” said Lenamon, who also represented Grady in 2010.

“The death penalty is final. Keeping relevant information such as the QEEG from jurors will be problematic and costly. If the Florida Supreme Court decides that these judges are mistaken about the use of the QEEG, it will be yet another impediment to the justice system.”

Electroencephalogram tests, known as EEGs, record electrical energy in the brain through sensors attached to the head. The results are displayed as squiggly lines on paper, and the tests have been in use for decades.

In recent years, computers have been used to create the “Quantitative EEG,” known as QEEG, which translates the results into a digital image of a patient’s brain to help analyze brain-wave frequencies. The technology is often used to detect brain damage in stroke and epilepsy patients.

The use of the QEEG has been debated for years within the medical and neurological science communities.

No state criminal court had allowed jurors to consider the QEEG until the case of Grady Nelson, who was convicted of first-degree murder in July 2010. Nelson stabbed his wife 61 times, then raped and stabbed her 11-year-old mentally disabled daughter.

His defense lawyers said the QEEG showed Nelson’s brain damage and explained why he had a propensity for violence and acting impulsively.

After Nelson’s conviction, Judge Jacqueline Hogan Scola ruled that the QEEG’s “methodologies are sound, the techniques are sound, the science is sound.”

“I feel comfortable that the average juror can figure out what they believe and disbelieve, just like any other battle of the experts,” Scola said.

During the penalty phase, a defense doctor presented jurors with a computer slide show replete with colorful graphics of the brain, and explanations of the effects of damage to the frontal lobe. Two months later, jurors split, 6-6, on whether Nelson should be executed — which, by law, meant an automatic life sentence.