The BAU is re-investigating whether a California serial killer is actually guilty of the crimes he confessed to in 2004 because he is set to be executed in two weeks, yet California has had a de facto moratorium on executions since 2006, so unless Criminal Minds takes place in an alternate reality, there's no way California would be carrying out an execution in 2014.
Even if California were carrying out executions, it is unlikely that someone who was convicted in 2004 would be executed so quickly. As of 2013, there were more than 700 individuals on California's death row, some of whom had been convicted in the 1980s. Even if the individual had chosen not to appeal his sentence--and in this case he has--there is a lengthy automatic-appeals process that would likely see other individuals, who have exhausted all their appeals, executed before him.
Even if California were carrying out executions, it is unlikely that someone who was convicted in 2004 would be executed so quickly. As of 2013, there were more than 700 individuals on California's death row, some of whom had been convicted in the 1980s. Even if the individual had chosen not to appeal his sentence--and in this case he has--there is a lengthy automatic-appeals process that would likely see other individuals, who have exhausted all their appeals, executed before him.
San Jose, CA does not have an FBI field office. The closest field office for the FBI is in San Francisco.
When Garcia is showing the team the slides regarding Sam Russell, the pictures of the victims appear with the title "THEY DIED IN VEIN". While this is a technical error ("vain" instead of "vein"), this is a reference to the allegation that Sam Russel was given IV drugs in exchange for false confessions.
When Garcia gets the email returning the police file from Shane, the email sender was misspelled to be from "Uknown".
In the opening, Hotch and Morgan are both there when Penelope Garcia is arrested and offered a choice between prison and joining the FBI. She makes a suggestive remark to Morgan, who then uncuffs her and says, "Welcome to the team." However, in a flashback during Tabula Rasa (2008), Morgan sees Garcia and asks who she is. Reid answers, "Ah, Gomez, I think ". When she doesn't answer to Gomez, Morgan resorts to using the familiar term of endearment, "Baby Girl!" It seems very unlikely that if he and Hotch went to San Francisco specifically to arrest Penelope, that Morgan would not have remembered her name.
Retired San Jose Police detective Cooper says he does not want the killer to get out of the gas chamber, but since a 1994 court ruling declared that death by gas is unconstitutional, all subsequent California executions have been by lethal injection. As a police officer who retired as late as 2010, it is unlikely that Det. Cooper wouldn't be aware of how the State of California executes those on death row.
Reid calls the Star Chamber a 17th century court but it actually started in the 15th century.
Garcia, a supposed computer genius, refers to SQL by saying each letter. When referencing SQL, it's pronounced like "sequel".