Alfredo Prieto has been convicted of murdering three people, raping two of them, and DNA or ballistics link him to another six homicides and two rapes. That is nine slayings in a little more than two years. Four of his victims were in Northern Virginia. He is one of the “great” unrecognized serial killers of our time. Yet a recent Supreme Court ruling has revived the prospect that he could avoid the three death sentences he currently faces, because his defense raised the possibility that he was intellectually disabled, and the news media have begun discussing Prieto as a serious candidate for post-conviction relief. Specifically, Virginia law defines “mental retardation” in part by test scores, which the Supreme Court prohibited, and Prieto had IQ test scores both above and below the state cut-off.

For someone who has followed Prieto for almost a decade, and watched three of his capital murder trials, the idea that he had any serious mental deficiency would appear to be mighty difficult to prove now, considering all we know about him now.  Besides the fact that Prieto apparently committed eight homicides which were not connected to him for 17 years or more, he had four jury trials, three of which hinged on the issue of his mental capacity. Further, this is a fellow who filed a handwritten federal lawsuit against the Virginia Department of Corrections and last year won outright. Yes, this death row inmate successfully challenged Virginia’s policy of placing all death row inmates in solitary confinement. There are many other reasons to believe that Prieto should not be considered mentally deficient. Here are a number of largely undisputed facts about Prieto, currently residing in the Sussex I prison in Waverly, Va., which seem to indicate he is far from mentally deficient, either during his killing rampage or now.

• Prieto had an undeniably horrible childhood in war-torn El Salvador, and moved to Los Angeles in 1981, when he was 15. Though he did not speak any English, he not only assimilated but performed very well at a Los Angeles public high school, according to testimony at his Fairfax trials. It was only when he joined an L.A. gang that he veered off course. He married and had a daughter at 18.

• After doing time for a drive-by shooting in L.A., he moved to Arlington in 1988 to live with his father, who had been convicted of murder in El Salvador. He held jobs, he lived with a woman, he sired a son. In May 1988, he abducted, raped and fatally shot Tina Jefferson behind McKinley Elementary School. He left no evidence other than his DNA and the case remained unsolved for 17 years.

• In December 1988, he somehow abducted two people, Rachael Raver and Warren Fulton III, and rode with them to a vacant lot outside Reston. No one witnessed the abduction, no one knows how he crossed paths with the two clean-cut, athletic 22-year-olds. Prosecutors said Prieto made Fulton get on his knees and then executed him. Rachael Raver ran. Prieto shot her too, then raped her as she lay dying. He then took their car to Queens, N.Y. and abandoned it, without a trace of evidence. This case also remained unsolved for 17 years, and Prieto continued to work and live with his girlfriend, son and father in Arlington for another year, until his father raped an Arlington woman.

• In September 1989, Prieto is believed to have shot his fourth victim, Manuel Sermeno, in Prince William County, authorities say ballistics tests have shown. In February 1990, Prieto swiped the identification of his girlfriend’s brother and used his name as he returned to his old stomping grounds in the Riverside-Ontario area east of Los Angeles.

• In May 1990, another young couple, Stacey Siegrist and Tony Gianuzzi, were found shot to death in Rubidoux, Calif. Siegrist was raped, and DNA later matched Prieto.

• In June 1990, an older couple, Lula and Herbert Farley, were abducted and shot to death in Ontario, Calif. Ballistics matched with Prieto’s weapon, authorities say. His homicide total was now eight, and he had left almost no clues in any of them, particularly for 1990s-era technology.

• On Sept. 2, 1990, he and two of his friends abducted three young girls, took them to a vacant lot in Ontario and raped them. His friends let their victims leave. Prieto shot and killed his victim, 15-year-old Yvette Woodruff. But with two living witnesses and two co-conspirators, he was arrested within days. He was charged with capital murder, convicted in 1991 and sentenced to death in 1992. It would not be until 2005 that his DNA was entered into a national databank, and a match was made with the Fairfax and Arlington murders.

At that point, Prieto had been on death row in California for 13 years. California’s death penalty system is a joke, with an understood game played where capital cases are tossed back and forth between state and federal court. Prieto has now been on California’s death row for 22 years. Aware of this, then-Fairfax prosecutor Robert F. Horan Jr. extradited Prieto and put him on trial in Virginia, where the death penalty system is decidedly not a joke.

In Fairfax, Prieto was appointed two of the best defense lawyers in this region, if not the country, Peter Greenspun and Jonathan Shapiro. And they did phenomenal work for him, as seen by the results: In the first trial, where the defense argued that Prieto couldn’t be executed because he suffered from mental disability, with IQ test scores of 66 and 73 — Virginia has a legal threshold of 70 or below as a definition of “mental retardation” — the jury convicted him of capital murder, but in the sentencing phase, one juror revolted and a mistrial was declared.

A second full trial was held, and the jury sentenced Prieto to death. But Greenspun and Shapiro successfully appealed, arguing the jury’s verdict form was wrong. So a third trial was held, for sentencing only, with the mental issue again the linchpin. And again, after hearing the evidence of Prieto’s brutal childhood, his exposure to toxic chemicals, his IQ test scores and his involvement in three of the homicides, a jury sentenced him to die. His case, upheld in the state courts, is now in the federal courts.

So that’s three full jury trials where Prieto’s mental capacity was fairly fully examined, and only found to be deficient by one juror. And then came this recent development: Prieto filed a series of handwritten grievances at Sussex, followed by a federal lawsuit in 2012 in the Eastern District of Virginia, challenging both the visitation rules and the fact that he was summarily placed in isolation without so much as an evaluation, as all death row inmates in Virginia are. (The full lawsuit is below.) Prisoners’ “pro se” lawsuits are very rarely successful, to put it mildly, though Prieto did later acquire a lawyer. U.S. District Judge Leonie Brinkema is not a bleeding heart judge, to put it mildly. But Brinkema ruled in November that Prieto had a point, and that Virginia now must screen all death row inmates before placing them in solitary. Virginia is appealing.

Now, Prieto still has some hurdles to overcome while invoking the recent Supreme Court ruling that states such as Virginia may not draw a bright line (such as an IQ test score) to differentiate between deficient and not-deficient. One of those hurdles is the judge in his federal habeas corpus case, U.S. District Judge Henry Hudson, a former state and federal prosecutor, former U.S. marshal, and former Fairfax County circuit judge. He is no shrinking violet, to put it mildly. And Hudson may rule that the juries considered the totality of Prieto’s life and times in deciding he wasn’t mentally deficient, and reject Prieto’s death sentence appeal.

But Prieto can always appeal that, too.

Below is Prieto’s federal lawsuit which, with some subsequent help from lawyers, overturned a Virginia prisons policy of placing all death row prisoners in solitary confinement: