A Santa Clara County case has been called “a prosecutor’s nightmare” after the wrong identical twin was issued murder charges that were then dropped and shifted to his brother.

Nearly two weeks ago, 22-year-old San Jose State University student Richard Phan was stabbed and killed during a fight in which he was trying to be a mediator.

Duc Tong, 18, was initially charged by prosecutors in the murder, but this charge was later dropped and reassigned to his twin brother, Ahn Tong. Duc Tong has not been cleared entirely in the case, still facing a lesser charge. Both men have been in jail since their arrest in connection with the Jan. 26 crime, after which they fled and were later apprehended.

tong twins

Anh Tong (left) and Duc Tong (right) were arrested after a fatal stabbing took place on Jan. 26. Duc Tong was originally charged with the murder, but this charge was later dropped and shifted to his twin brother Anh. (Image source: San Jose Police Department)

“New and credible information came to light that required a re-evaluation of the roles,” Deputy District Attorney Dan Fehderau told the San Jose Mercury News of the change in charges.

Based on new details, which the Mercury News reported are not being released by authorities, Duc Tong is now being accused of “aiding his brother in avoiding arrest or conviction in the murder.”

Fehderau added that the prosecution is confident in the filed charges and put a positive spin on the incident.

“This is an example of police keeping an open mind, pursuing an investigation and wanting to get it right,” he said.

But legal analyst Steven Clarke told KPIX-TV that the mixup could cause problems in court.

“A jury is going to look at this case now with some skepticism because the prosecution’s theory has completely shifted by changing their theory from one twin to the other,” Clarke said, according to the news station.

Watch KPIX-TV’s report about the confusion:

Clarke told the Mercury News that the prosecution could be called into question as to why it didn’t wait to file charges. Even still, “it’s better to get it right,” he said.

Using DNA evidence in cases against identical twins has been difficult in the past, but late last year new research found slight differences in the genetic code of twins that could prove useful in criminal trials.

(H/T: San Francisco Gate)