The masked man seen in doorbell camera video who is suspected of abducting Nancy Guthrie appears to have been at her front door earlier than Feb. 1, the night police believe she was kidnapped, a law enforcement source confirmed to CBS News. The information was first reported by ABC News.

An image the FBI released of the suspect at the 84-year-old’s front door, in which he is seen without a backpack, was captured by her Nest doorbell camera sometime prior to the date of the suspected abduction. It is unclear how many days before Feb. 1 the video of the man without a backpack was taken.

The FBI released the images and videos of the suspect, most of which showed him carrying a backpack and wearing a face mask and gloves, on Feb. 10 and asked for the public’s help in identifying the man seen in the videos. So far, investigators have not identified a suspect in the case.

Pima County Sheriff Chris Nanos told CBS News that the information about the timing of the video of the man not wearing a backpack is not coming from the Pima County Sheriff’s Department or the FBI. 

The sheriff’s office later said Monday night in a statement, “There is no date or time stamp associated with these images. Therefore, any suggestion that the photographs were taken on different days is purely speculative.”

A spokesperson for the FBI did not immediately respond to a request for comment. 

In a previous statement from Feb. 10, Nanos said, “The FBI and Pima County Sheriff’s Department have been working closely with our private sector partners to continue to recover any images or video footage from Nancy Guthrie’s home that may have been lost, corrupted or inaccessible due to a variety of factors, including the removal of recording devices. The video was recovered from residual data located in backend systems.”

A spokesperson for Google, the company that owns Nest cameras, had previously told CBS News that it is assisting law enforcement in an investigation but could not provide further details due to the ongoing investigation. CBS News reached back out to Google about when the earlier video of the man without the backpack was taken, but a spokesperson did not immediately respond to a request for comment.

The FBI has said the backpack the suspect was seen carrying is a black, 25-liter Ozark Trail Hiker Pack backpack. CBS News first reported that the backpack is sold exclusively at Walmart.

Nanos previously called the backpack “one of the most promising leads” in the case.

It was not clear if the backpack was purchased online or at a store, but investigators have been reviewing surveillance video footage from local Walmart locations, Nanos said. The company has also provided authorities with records of all Ozark Trail Hiker purchases from the past several months, Nanos said.

The man seen in the doorbell footage has been described as being about 5 feet, 9 inches or 5 feet, 10 inches tall with an average build.

Nanos said last week that investigators have not ruled out the possibility that an accomplice aided the suspected kidnapper, although no persons of interest have been named in the investigation. He also said Guthrie’s family members, which include “Today” show co-host Savannah Guthrie and her two siblings, had been cleared as suspects.

DNA from an unknown male was found on a glove that was recovered near Nancy Guthrie’s home and appeared to match the ones the suspect was seen wearing in the doorbell video. No match was found when the DNA was submitted to the national database maintained by the FBI, known as CoDIS.