Moscow, Idaho, police are trying to gather more information on students Xana Kernodle and boyfriend Ethan Chapin's whereabouts before they were murdered at a rental home near campus, according to a report.
The timeline of Chapin and Kernodle, both 20, "seems to be one of the larger areas that we don't have a lot of information in," Idaho State Police spokesman Aaron Snell told ABC News.
"So, being able to locate what they did that night, and maybe who they contacted, maybe any routes that they took home, that would be important for the investigation."
The couple were at Chapin's frat house, Sigma Chi, from 9 p.m. to 1:45 a.m., before returning to Kernodle's home Nov. 13, police previously said.
Chapin, Kernodle and her roommates, Madison Mogen, 21, and Kaylee Goncalves, 21, were stabbed to death between 3 a.m. and 4 a.m. that morning.
Kaylee Goncalves' injuries were "more brutal" than the other victims, NewsNation reported, citing a source.
Snell told ABC News that police did not disclose this information to Goncalves' family but were also not refuting it.
Steve Goncalves told Fox News Digital that the "means of damage" for his daughter and her best friend, Mogen, were different, even though the best friends were sleeping in the same bed when they were attacked. He wouldn't elaborate further.
The investigation has entered its fourth week, and police have said they don't have a suspect and haven't recovered the "fixed-blade knife" they believe was the murder weapon.
Police also addressed questions about Goncalves' dog, Murphy, who was found at the home after the killings.
"We have not determined if the dog was inside the residence during the murders or not," Snell told ABC News. "What we do know is that the dog was inside when officers arrived. The dog did not appear to have any evidence on it."
In a press release Monday, police said they're looking for any information that will "add context to the picture investigators are creating" of what happened before and after the mass murder.
"Your information, whether you believe it is significant or not, might be one of the puzzle pieces that help solve these murders," Snell told the news station.