An Ohio couple was killed at home while their 2 children were inside. Here’s a timeline of the case so far.

(CNN) — More than a week after a Columbus, Ohio, couple was shot dead in their home – the same place they exchanged wedding vows and were raising their young family – their killer is still at large and police have released few details about their investigation.

Spencer and Monique Tepe, 37 and 39, were killed in the early hours of December 30 while their two young children were inside the residence. Their children, ages 1 and 4, were not physically harmed, police said; they and the family’s dog are now in the care of relatives, their brother-in-law told CNN.

A notable development in the case came Monday, when the Columbus Division of Police released surveillance footage showing a “person of interest” walking in the alley near the couple’s home in the Weinland Park neighborhood, just north of downtown. It was taken during the timeframe investigators believe the couple was killed, police said.

Police have not discussed possible suspects or a motive in a case they are investigating as a double homicide. Mystery has shrouded the killings since police revealed early on there were no obvious signs of forced entry and no firearm was found at the scene, CNN affiliate WSYX reported.

As law enforcement continues to ask the public for information, here’s a timeline of what we’ve learned since the Tepes were killed:

December 29

The last publicly known sighting of Spencer Tepe is on this day, a Monday.

After a friend told a dispatcher the following day he saw a body, the dispatcher asked when he’d last spoken with Tepe, according to 911 calls reported by WSYX. The friend responded: “Yesterday, I suppose.”

In a follow-up question, the dispatcher asked whether Spencer Tepe had been ill. The friend responded, “No, no. I was just with him yesterday.”

December 30

Sometime between 2 and 5 a.m. is when the Tepes are killed, according to Columbus police. Detectives believe the Tepes were killed in the upstairs of their home.

Police have not responded to CNN’s questions about why or how they isolated that three-hour window. Investigators later asked for any video footage from that time period.

The first 911 call comes at 8:58 a.m. from Dr. Mark Valrose, the owner of Athens Dental Depot, where Spencer Tepe was a dentist. Valrose, calling from his vacation in Florida, says employees told him Spencer Tepe hadn’t shown up for work.

Valrose asks police to conduct a wellness check, saying: “He is always on time, and he would contact us if there were any issues,” according to the recording.

“I don’t know how else to say this, but we are very, very concerned. This is very out of character for him,” he continues. “We can’t get in touch with his wife, which is probably the more concerning thing.”

At 9:22 a.m., an officer arrives at the home to perform the check, but no one answers the door and they leave, WSYX reported, citing police records.

Around 30 minutes later, Spencer Tepe’s colleagues and a friend arrive at the home, but they also do not get a response, the dispatch records showed. A man at the scene calls 911 at 9:56 a.m., saying he hears children inside.

The dispatcher tells him the police are being sent back to the home.

Two minutes later comes a third 911 call, this time from another colleague who says they’ve been unable to reach Spencer Tepe for about three hours, according to the recordings.

Around 10:03 a.m., the friend who said he’d seen Spencer Tepe on Monday calls 911 and is audibly distressed: “There’s a body,” he reports. The friend does not specify whether he is inside or outside the house, and he has not responded to CNN’s request for comment.

Columbus police officers are dispatched to the home at 10:04 a.m. to conduct a wellness check. At 10:11 a.m., medical personnel pronounce both victims deceased, the police statement said.

January 2

The Tepe family releases a statement to CNN saying they are “devastated by the tragic and senseless loss” of the beloved couple.

“We are heartbroken beyond words,” the statement reads.

The family says they are “committed to seeing this tragedy fully and fairly brought to justice” and to honoring them by protecting the future of their two children.

The couple, their family says, were “extraordinary people whose lives were filled with love, joy, and a deep connection to others.”

January 5

Columbus police give their first significant update in days as they release surveillance footage from the early hours of December 30 showing a person wearing light-colored pants and a dark hoodie pulled over their head.

The person keeps their head down as they trudge along a snow-lined alley in the dark, the video showed. Police do not say why they’re describing the person in the video as a “person of interest” and ask the public for information.

Columbus police acknowledge there are “questions and concerns surrounding this tragic incident,” saying detectives are “working diligently to solve this case.”

“We want to thank the community for the tips we have received,” police say. “We will continue to update you as the investigation progresses.”

The Franklin County Coroner’s Office tells CNN the Tepes’ deaths are “apparent homicides by gunshot wounds” but said the official autopsy reports could take weeks to complete.

January 6

A spokesperson for the Columbus police, Sgt. Joe Albert, responds to CNN’s questions about why they are interested in the person seen in the surveillance footage and why they are not considering them a suspect.

“In order to maintain the integrity of the investigation, we cannot answer that question right now,” Albert says.

Columbus police have not answered CNN’s questions about whether detectives have identified a suspect or possible motive; how the assailant got into the house; whether the couple was targeted; and whether there is any threat to the public.