(NewsNation) — Idaho police announced they will be cleaning the house where four University of Idaho students were slain in November, which indicates they have high confidence that all DNA evidence has been collected at the scene.

Could any of that DNA finally catch the killer? First, police would need to find a match.

It’s been six weeks since the four college students were found stabbed to death in an off-campus rental house in Moscow, Idaho, and police still have not released the names of any suspects. They’re currently seeking information about a white Hyundai Elantra that was near the house at the time of homicides.

Investigators have been in and out of the house multiple times, likely to collect any and all DNA evidence. But even if the killer left a trace of themselves, using that DNA to find them won’t be as easy as television makes it out to be.

Police run DNA samples against those of criminals, meaning a hit would only be present if the perpetrator has had run-ins with the law before. However, genetic geneology could prove useful in broadening the search.

CeCe Moore, chief genetic genealogist at Parabon NanoLabs, whose groundbreaking DNA techniques have helped solved 250 criminal cases, explained the process in which a DNA sample is tested against those in a database kept by commercial genealogy companies.

“We can use these databases to broaden out, looking for relatives, usually distant cousins of that unknown perpetrator, and we can reverse engineer his or her family tree from their common ancestors,” Moore said Thursday on “CUOMO.”

Family Tree DNA and GEDmatch are the two services that have agreed to work with law enforcement, Moore said. The largest two services, Ancestry DNA and 23andMe, bar the use of DNA matching by law enforcement.

“In (Family Tree DNA and GEDmatch) databases, you have to at least not opt out of law enforcement matching,” Moore said of privacy concerns. “So, we’re not using anyone who hasn’t agreed to that expressly.”

Police have been tight-lipped about information in the case thus far, a decision that has drawn criticism from the victims’ families and larger Moscow community. One of the families has hired a lawyer who has questioned the ability of Moscow police to lead the investigation.

As for the DNA aspect, “I would think in a case like (this), we would have seen an arrest quite quickly if they had gotten that match in their law enforcement databases,” Moore said.

DNA questions aside, the cleaning of the house indicates the evidence collection phase of the investigation there is closing.

“At this point, they are very confident that they have a done a full-scale evaluation of the evidence, that they’ve collected it and they’ve sent it off to the lab,” said Jennifer Coffindaffer, a former FBI agent. “This is time to move on from that crime scene.”