Edward T. Blake, Pioneer of Using DNA to Prove Innocence, Dies at 80

Edward T. Blake, a foren­sic sci­en­tist who helped pio­neer the use of DNA analy­sis in crim­i­nal cas­es and whose work helped exon­er­ate more than 50 peo­ple, includ­ing those on death row, died in August 2025 at age 80 from pan­cre­at­ic can­cer. Dr. Blake was the first foren­sic sci­en­tist to use poly­merase chain reac­tion test­ing, or PCR, on crime-scene DNA. The tech­nique allowed Dr. Blake to extract usable genet­ic infor­ma­tion from evi­dence sam­ples that could not pre­vi­ous­ly be test­ed because of old age, small quan­ti­ty, or severe degradation.

Dr. Blake’s work coin­cid­ed with a peri­od in which the crim­i­nal legal sys­tem began to con­front the use of unre­li­able foren­sic evi­dence in con­vic­tions. The PCR test­ing used by Dr. Blake was among the few foren­sic tools that could defin­i­tive­ly exclude peo­ple who were accused of being involved in crimes. In 1988, he helped con­tribute to the first DNA exon­er­a­tion, prov­ing that Gary Dotson, who had served 8 years in prison for a sex­u­al assault, could not have been the source of the bio­log­i­cal evi­dence from the crime he was accused of com­mit­ting. Just five years lat­er, in 1993, Dr. Blake’s work helped free Kirk Bloodsworth from death row in Maryland — the first death-sen­tenced per­son to be exon­er­at­ed through DNA evidence.

“Ed was a guy who saw things in black and white,” said Maurice Possley, a for­mer reporter for The Chicago Tribune who inves­ti­gat­ed wrong­ful con­vic­tions. ​“Like, ​‘You can come up with all kinds of dif­fer­ent the­o­ries about why some­thing doesn’t exon­er­ate this per­son. But what I’m telling you is this person’s bio­log­i­cal mate­ri­als is not present.’ And that’s pret­ty defin­i­tive.” Peter Neufeld, co-founder of the Innocence Project, com­pared Dr. Blake to Ted Williams, the base­ball play­er regard­ed as among the great­est of all time. ​“In foren­sic sci­ence, there are a bunch of .300 hit­ters, and there’s Ted Williams. Ed Blake is Ted Williams.”

As an under­grad­u­ate at the University of California, Berkeley, in the 1960s, Dr. Blake switched his stud­ies from physics to foren­sics. ​“There were just so many things going on in soci­ety, and our cul­ture was under­go­ing a lot of changes,” he told the Associated Press in 1995. ​“I want­ed to be involved in a field that was more prac­ti­cal­ly ori­ent­ed and soci­etal­ly ori­ent­ed, and so some­how I just grav­i­tat­ed to the foren­sic sci­ence pro­gram.” He would go on to receive his bachelor’s degree in 1968 and a doc­tor­ate in crim­i­nol­o­gy in 1976, also from Berkeley.

In the mid-1980s, Dr. Blake’s con­sult­ing com­pa­ny, Forensic Science Associates, occu­pied the same build­ing as a biotech firm that had devel­oped PCR test­ing. After con­sult­ing with mol­e­c­u­lar geneti­cist Henry Erlich of Cetus Corporation, Dr. Blake began to use PCR test­ing on degrad­ed tis­sue sam­ples, which proved to be a trans­for­ma­tive tech­nique for foren­sic analy­sis. Alternative meth­ods of DNA analy­sis exist­ed at the time; how­ev­er, they required large amounts of bio­log­i­cal mate­ri­als to be able to make an iden­ti­fi­ca­tion. Often times, crime scene evi­dence was not sub­stan­tial enough or too degrad­ed to be test­ed by these meth­ods. Dr. Blake was known by his peers for hav­ing an unwa­ver­ing insis­tence on sci­en­tif­ic accu­ra­cy. ​“Those who know Blake believe that a stick of dyna­mite siz­zling under his nose would not cause him to alter a dot or com­ma in a lab­o­ra­to­ry report,” wrote Jim Dwyer for Newsday in 1994.

Dr. Blake’s work took on height­ened sig­nif­i­cance as aware­ness grew about how unre­li­able foren­sic evi­dence had con­tributed to wrong­ful con­vic­tions. His DNA analy­sis pro­vid­ed a defin­i­tive means of excul­pat­ing sus­pects in cas­es where tra­di­tion­al foren­sic meth­ods had offered only subjective assessments. 

The lega­cy of ques­tion­able foren­sic sci­ence con­tin­ues to be seen in cas­es today. Robert Roberson, a Texas death-sen­tenced pris­on­er, was con­vict­ed on the basis of ​“Shaken Baby Syndrome” (SBS), a diag­no­sis that has since been refut­ed by most med­ical experts. In 2024, the Texas Court of Criminal Appeals over­turned an SBS con­vic­tion in anoth­er case and recent­ly grant­ed Mr. Roberson a last minute stay of exe­cu­tion under Texas’ junk sci­ence law, which allows for recon­sid­er­a­tion of con­vic­tions when the sci­ence relied upon has been dis­cred­it­ed. Medical experts who reviewed the evi­dence in Mr. Roberson’s case have con­clud­ed that his 2‑year-old daugh­ter Nikki actu­al­ly died from acci­den­tal and nat­ur­al caus­es, not abuse.

Cases like Mr. Roberson’s under­score the evolv­ing under­stand­ing of foren­sic sci­ence in crim­i­nal cas­es. Dr. Blake’s career demon­strat­ed what this rig­or looks like: his work estab­lished that foren­sic sci­ence can be a vital tool in ensur­ing accu­ra­cy and fair­ness in criminal cases.