MIAMI, FL — A 37-year-old undocumented immigrant from Honduras has been accused of murdering two women — both of whom he had sex with — in what police feared had the makings of a serial killer case. Juan Hernandez-Caseres could face the death penalty in connection with the murders of Neidy Roche and Ann Farran. But his legacy could have been far worse had it not been for a warm South Florida day and a can of Coca-Cola.

Miami-Dade police said Hernandez-Caseres confessed to killing the women in separate incidents in March and June after paying them for sex. But the break in the case came on Thursday when he reached for a Coke as he was being watched by Miami-Dade detectives. "During the surveillance, investigators were able to observe 'the subject' drinking out of a Coca-Cola soda can," according to court documents filed in the case. "Investigators then observed 'the subject' attempt to throw the Coca-Cola in a dumpster. However, the Coca-Cola can struck the side of the dumpster and fell to the ground."

The alleged murderer's biggest mistake turned out to be littering.

"Investigators then recovered the can shortly after 'the subject' walked away," investigators explained in the court documents. "A male DNA profile was obtained from the Coca-Cola can."

But court documents also reveal that months before Hernandez-Caseres was accused of murdering his first victim, he had another run in with the law, which could have turned up his illegal immigration status. Hernandez-Caseres was arrested by Miami-Dade police on Nov. 26 for false report of an armed carjacking. But it was not clear whether his illegal immigration status was flagged by U.S. immigration officials at that time.

Spokesman Nestor Yglesias with U.S. Immigration and Customs Enforcement in Miami told Patch on Wednesday that federal officials lodged an immigration detainer against Hernandez-Caseres following his arrest on murder charges but couldn't comment as to whether a similar detainer was filed following the November arrest.

"ICE is focused on identifying, arresting and removing public safety threats, such as convicted criminal aliens and gang members as well as individuals who have violated our nation's immigration laws," Yglesias said.

While his immigration status may not have surfaced until he was arrested for murder, it is clear that the Coke discarded by Hernandez-Caseres provided a crucial link in the investigation. Forensic specialists from the Miami-Dade Police Department's Forensic Services Bureau were able to compare DNA samples from the Coke can to traces of DNA left behind on Roche's neck and left hand.