So who did it? DNA test fingers twins.

One of the most spectacular robberies in German history could end in an acquittal because one of the accused shares his DNA with a twin.

Last January’s multi-million-dollar heist at Berlin’s famous Kaufhaus des Westens department store had all the trappings of a big-budget action flick. Local police believe thieves climbed onto the store’s roof before carefully lowering themselves into its main hall. Once there, they broke into display cases and lifted their contents—all without setting off any motion detectors or alarms. By the time they were done, nearly $10 million worth of jewels and luxury watches were gone.

Investigators initially thought they’d cracked the case when they stumbled onto a glove at the crime scene that contained clearly identifiable DNA. Less than three weeks after the robbery, police arrested two brothers in connection with the heist. But that’s when the case got complicated. It turns out the same discarded glove that got Abbas and Hassan O. arrested could also end up being what gets them off the hook.

Abbas and Hassan are identical twins and the genetic analysis used in criminal cases in Germany can’t distinguish one’s DNA from the other’s. According to an expert interviewed by Der Tagesspiegel, “monozygotic twins can only be identified by their fingerprints,” none of which were found at the crime scene. Under German law, the suspects must be proven independently guilty of a crime to be convicted; should both insist the other committed the crime, officials fear the brothers could escape punishment altogether. Germany also limits the extent to which DNA evidence can be tested, meaning more advanced procedures that could distinguish the twins’ DNA would be inadmissible.

Research teams from around the world have been working on finding a way around the troublesome DNA quandary. But even if they succeed, at least two other issues remain: the loot, and a third suspect caught on the store’s CCTV cameras, are still nowhere to be found.