In the news....
A Texas jury found him guilty of murder. A computer algorithm proved his innocence.
Excerpted....
Nearly a decade into his life sentence for murder, Lydell Grant was escorted out of a Texas prison in November with his hands held high, free on bail, all thanks to DNA re-examined by a software program.
"The last nine years, man, I felt like an animal in a cage," Grant, embracing his mother and brother, told the crush of reporters awaiting him in Houston. "Especially knowing that I didn't do it."
Now, Grant, 42, is on a fast-track to exoneration after a judge recommended in December that Texas' highest criminal court vacate his conviction. His attorneys are hopeful a ruling is made in the coming weeks.
But for Grant, to get to here hinged on two necessary prongs: the DNA evidence, which was reanalyzed through an emerging software that has also come under scrutiny, and an unprecedented decision to use the findings to conduct an FBI criminal database search that was initiated by a third party not part of the initial investigation. That ultimately led to the discovery of a new suspect, who has been charged after police say he confessed.
The search process used in Grant's case has enormous potential to solve cold cases or re-evaluate other convictions that could pave the way for more exonerations nationwide, forensic scientists say.
"There's probably 5,000 or 6,000 innocent people in Texas prisons alone," said attorney Mike Ware, executive director of the Innocence Project of Texas, which is representing Grant. "How many of them could benefit from such a reanalysis of DNA that was used to convict them? I don't really know, but this is a historic case that could open the door for those who thought it was shut forever."
A match in the database
Grant's ordeal began in December 2010, when Aaron Scheerhoorn was stabbed outside a Houston gay bar. Authorities said Scheerhoorn, who was bleeding from his abdomen, had run to the bar's entrance seeking help from horrified bar patrons and employees. The witnesses described the killer as a black man, about 25 to 30 years old, and around 6 feet tall. Police told local media it may have been a "crime of passion."
A tip came in about a car that might belong to the suspect. Five days later, an officer pulled over a vehicle matching its description and Grant, who at the time was driving on a suspended license, was taken in for questioning.
Investigators also interviewed seven witnesses, all but one of whom picked out Grant as the suspect from a photo lineup.
Grant, then 33, had a criminal record going back several years, including for aggravated robbery, marijuana use and theft. But he maintained his innocence in the stabbing, said he never met Scheerhoorn and produced an alibi for his defense.
At Grant's 2012 trial, prosecutors centered their case around the eyewitness testimony — a practice that the Innocence Project argues plays a major role in defendants being wrongfully accused. In addition, jurors heard about DNA collected from fingernail scrapings from Scheerhoorn's right hand. The DNA was actually a mixture of two people: the victim and a second male profile.
Houston's police crime lab at the time was unable to conclude that the other genetic material was Grant's, and the state's expert's testimony suggested to the jury that it "could not be excluded."
Jurors also heard from Grant's alibi, who said he was with him on the night Scheerhoorn was murdered, but his testimony failed to sway them, court documents show.
Grant was found guilty of first-degree felony murder. From his jail cell in Harris County, he began writing to anyone he thought could help.
A letter eventually landed on a pile at the Innocence Project of Texas, which receives hundreds of inmate mail each month. In 2018, it was referred to the Texas A&M School of Law, which partners with the Innocence Project of Texas.
"We knew at the very least the prosecutor put on inaccurate testimony at trial," Ware said. "We didn't know where the facts were going to lead to."
The law students got to work, paying particular attention to the DNA report that described the mixture of genetic materials. In 2011, the Houston crime lab had analyzed it using a traditional method in which a forensic scientist studies the genetic makeup of the DNA sample, which is translated into a type of graph that can be reviewed manually, and determines the probability that a particular person's DNA matches the sample. But when a sample includes a mixture of DNA from more than one person, it is increasingly difficult to separate and interpret the data. Flawed DNA readings by analysts have been known to ensnare innocent people.
After Ware and the students gave a fresh look at the original DNA report, they were convinced Grant's DNA could not have been a part of the mixture. In March 2019, Ware began working with Angie Ambers, a DNA expert and an associate professor of forensic science at the University of New Haven in Connecticut.
Ambers was familiar with a type of DNA technology known as "probabilistic genotyping."
"Years after Lydell Grant was convicted and sent to prison, there was a paradigm shift in how we interpreted DNA mixtures in criminal casework," she said. "Rather than having a human DNA analyst interpret a mixture of DNA, computer software programs were developed to reduce the subjectivity in interpretation."
Ambers learned of one such software program created by Cybergenetics, a small company in Pittsburgh that had done work analyzing DNA samples from unidentified victims of the 9/11 terror attacks.
It was worth a shot: Ware requested the raw DNA data from the Harris County District Attorney's Office, and then it was shared with Cybergenetics and run through its program, TrueAllele. (The name is a play off the word that signifies the different forms that a person's genes can take.)
The company offered a free preliminary screening, and the software did what a human could not: determine that Grant's DNA did not match the unknown male profile.
Ambers had a hunch that something was off when she first reviewed the case because of a large number of alleles present in the DNA mixture that were inconsistent with Scheerhoorn's or Grant's profiles. But she said that TrueAllele's discovery alone wouldn't guarantee Grant would be cleared of a crime.
Armed with this new evidence, the Innocence Project of Texas went a step further, prompting Cybergenetics to work with a partner crime lab in Beaufort County, South Carolina, which has access to a powerful FBI database known as the Combined DNA Index System, or CODIS.
Typically, federal, state and local law enforcement and government crime labs can upload an unknown profile into the database and compare it to one of the more than 14 million convicted criminals and those arrested already in the system for a possible match. The process, for instance, can help authorities link crimes from several scenes to a single person.
The South Carolina crime lab's search resulted in a hit. The DNA profile belonged to a man in Atlanta named Jermarico Carter, who police say left Houston shortly after Scheerhoorn's murder. Carter also has a lengthy criminal record, and Houston Police Chief Art Acevedo said in a statement in December that he confessed to the killing.
Acevedo at the time also issued a rare apology to Grant and his family "as they have waited for justice all these years."
Trusting the source code
Mark Perlin, the CEO of Cybergenetics and developer of TrueAllele, said the use of a probabilistic genotyping software's findings in CODIS is significant as it's the first time it was attempted because an independent party, the Innocence Project, requested it and not law enforcement. And most remarkably, it resulted in a match.
He touted his software, which runs DNA data through a statistical algorithm with some 170,000 lines of code, for being able to untangle DNA mixtures.
Those mixtures "have a complex pattern based on how much of each person is there along with distortions," Perlin said. "A computer can account for that and dig deeper into the data to get far more information."
A Texas jury found him guilty of murder. A computer algorithm proved his innocence.
Excerpted....
Nearly a decade into his life sentence for murder, Lydell Grant was escorted out of a Texas prison in November with his hands held high, free on bail, all thanks to DNA re-examined by a software program.
"The last nine years, man, I felt like an animal in a cage," Grant, embracing his mother and brother, told the crush of reporters awaiting him in Houston. "Especially knowing that I didn't do it."
Now, Grant, 42, is on a fast-track to exoneration after a judge recommended in December that Texas' highest criminal court vacate his conviction. His attorneys are hopeful a ruling is made in the coming weeks.
But for Grant, to get to here hinged on two necessary prongs: the DNA evidence, which was reanalyzed through an emerging software that has also come under scrutiny, and an unprecedented decision to use the findings to conduct an FBI criminal database search that was initiated by a third party not part of the initial investigation. That ultimately led to the discovery of a new suspect, who has been charged after police say he confessed.
The search process used in Grant's case has enormous potential to solve cold cases or re-evaluate other convictions that could pave the way for more exonerations nationwide, forensic scientists say.
"There's probably 5,000 or 6,000 innocent people in Texas prisons alone," said attorney Mike Ware, executive director of the Innocence Project of Texas, which is representing Grant. "How many of them could benefit from such a reanalysis of DNA that was used to convict them? I don't really know, but this is a historic case that could open the door for those who thought it was shut forever."
A match in the database
Grant's ordeal began in December 2010, when Aaron Scheerhoorn was stabbed outside a Houston gay bar. Authorities said Scheerhoorn, who was bleeding from his abdomen, had run to the bar's entrance seeking help from horrified bar patrons and employees. The witnesses described the killer as a black man, about 25 to 30 years old, and around 6 feet tall. Police told local media it may have been a "crime of passion."
A tip came in about a car that might belong to the suspect. Five days later, an officer pulled over a vehicle matching its description and Grant, who at the time was driving on a suspended license, was taken in for questioning.
Investigators also interviewed seven witnesses, all but one of whom picked out Grant as the suspect from a photo lineup.
Grant, then 33, had a criminal record going back several years, including for aggravated robbery, marijuana use and theft. But he maintained his innocence in the stabbing, said he never met Scheerhoorn and produced an alibi for his defense.
At Grant's 2012 trial, prosecutors centered their case around the eyewitness testimony — a practice that the Innocence Project argues plays a major role in defendants being wrongfully accused. In addition, jurors heard about DNA collected from fingernail scrapings from Scheerhoorn's right hand. The DNA was actually a mixture of two people: the victim and a second male profile.
Houston's police crime lab at the time was unable to conclude that the other genetic material was Grant's, and the state's expert's testimony suggested to the jury that it "could not be excluded."
Jurors also heard from Grant's alibi, who said he was with him on the night Scheerhoorn was murdered, but his testimony failed to sway them, court documents show.
Grant was found guilty of first-degree felony murder. From his jail cell in Harris County, he began writing to anyone he thought could help.
A letter eventually landed on a pile at the Innocence Project of Texas, which receives hundreds of inmate mail each month. In 2018, it was referred to the Texas A&M School of Law, which partners with the Innocence Project of Texas.
"We knew at the very least the prosecutor put on inaccurate testimony at trial," Ware said. "We didn't know where the facts were going to lead to."
The law students got to work, paying particular attention to the DNA report that described the mixture of genetic materials. In 2011, the Houston crime lab had analyzed it using a traditional method in which a forensic scientist studies the genetic makeup of the DNA sample, which is translated into a type of graph that can be reviewed manually, and determines the probability that a particular person's DNA matches the sample. But when a sample includes a mixture of DNA from more than one person, it is increasingly difficult to separate and interpret the data. Flawed DNA readings by analysts have been known to ensnare innocent people.
After Ware and the students gave a fresh look at the original DNA report, they were convinced Grant's DNA could not have been a part of the mixture. In March 2019, Ware began working with Angie Ambers, a DNA expert and an associate professor of forensic science at the University of New Haven in Connecticut.
Ambers was familiar with a type of DNA technology known as "probabilistic genotyping."
"Years after Lydell Grant was convicted and sent to prison, there was a paradigm shift in how we interpreted DNA mixtures in criminal casework," she said. "Rather than having a human DNA analyst interpret a mixture of DNA, computer software programs were developed to reduce the subjectivity in interpretation."
Ambers learned of one such software program created by Cybergenetics, a small company in Pittsburgh that had done work analyzing DNA samples from unidentified victims of the 9/11 terror attacks.
It was worth a shot: Ware requested the raw DNA data from the Harris County District Attorney's Office, and then it was shared with Cybergenetics and run through its program, TrueAllele. (The name is a play off the word that signifies the different forms that a person's genes can take.)
The company offered a free preliminary screening, and the software did what a human could not: determine that Grant's DNA did not match the unknown male profile.
Ambers had a hunch that something was off when she first reviewed the case because of a large number of alleles present in the DNA mixture that were inconsistent with Scheerhoorn's or Grant's profiles. But she said that TrueAllele's discovery alone wouldn't guarantee Grant would be cleared of a crime.
Armed with this new evidence, the Innocence Project of Texas went a step further, prompting Cybergenetics to work with a partner crime lab in Beaufort County, South Carolina, which has access to a powerful FBI database known as the Combined DNA Index System, or CODIS.
Typically, federal, state and local law enforcement and government crime labs can upload an unknown profile into the database and compare it to one of the more than 14 million convicted criminals and those arrested already in the system for a possible match. The process, for instance, can help authorities link crimes from several scenes to a single person.
The South Carolina crime lab's search resulted in a hit. The DNA profile belonged to a man in Atlanta named Jermarico Carter, who police say left Houston shortly after Scheerhoorn's murder. Carter also has a lengthy criminal record, and Houston Police Chief Art Acevedo said in a statement in December that he confessed to the killing.
Acevedo at the time also issued a rare apology to Grant and his family "as they have waited for justice all these years."
Trusting the source code
Mark Perlin, the CEO of Cybergenetics and developer of TrueAllele, said the use of a probabilistic genotyping software's findings in CODIS is significant as it's the first time it was attempted because an independent party, the Innocence Project, requested it and not law enforcement. And most remarkably, it resulted in a match.
He touted his software, which runs DNA data through a statistical algorithm with some 170,000 lines of code, for being able to untangle DNA mixtures.
Those mixtures "have a complex pattern based on how much of each person is there along with distortions," Perlin said. "A computer can account for that and dig deeper into the data to get far more information."