Authorities arrested Bryan Kohberger almost seven weeks after four University of Idaho students were killed, taking him into custody at his parents’ home in Pennsylvania, where an attorney said he had traveled for the holidays.

While it took almost two months for authorities to publicly name a suspect, police – who faced mounting criticism while the investigation outwardly appeared at a standstill – had begun focusing on Kohberger as a suspect weeks earlier.

Among the most notable pieces of evidence was a witness account from one of the victims’ surviving roommates, who told police she saw a man dressed in black inside the house the morning of the killings, according to a probable cause affidavit released last week. The witness described the man as about 5-foot-10 or taller and not very muscular but athletically built with bushy eyebrows, it said.

Investigators were also drawn to a white sedan seen in local surveillance footage in the area around the home. By November 25, they had told local law enforcement to look out for the car, by then identified as a Hyundai Elantra.

Days later, officers at Washington State University, where Kohberger was a PhD student in criminal justice, found such a vehicle and discovered it was registered to Kohberger, the affidavit says.

When investigators searched for his driver’s license information, they found it consistent with the description of the man dressed in black provided by the roommate, the affidavit says, specifically noting his height, weight and bushy eyebrows.

Kohberger got a new license plate for his car five days after the killings, the affidavit says. When he was arrested in Pennsylvania last week, a white Elantra was found at his home, according to Monroe County Chief Public Defender Jason LaBar, who represented the suspect in his extradition.

Other evidence listed in the affidavit included phone records showing Kohberger’s phone had been near the victims’ home at least a dozen times since June. Records also show the phone near the site of the killings hours later, between 9:12 a.m. and 9:21 a.m., the document says.

Additionally, trash authorities recovered from Kohberger’s family home revealed a DNA profile linked to DNA on a tan leather knife sheath found lying on the bed of one of the victims, the affidavit said. The DNA recovered from the trash is believed to be that of the biological father of the person whose DNA was found on the sheath, it said.

Kohberger was also surveilled for four days before his arrest, a law enforcement source told CNN. During that time, he was seen putting trash bags in neighbors’ garbage bins and “cleaned his car, inside and outside, not missing an inch,” according to the source.

A court order prohibits the prosecution and defense from commenting beyond referencing the public records of the case.