Savannah Guthrie returned to co-hosting NBC’s “Today” show on Monday, her first time on the program since her mother’s disappearance in Arizona, according to an Associated Press timeline of the case. The search for Nancy Guthrie, an 84-year-old mother of three, has continued since she was reported missing Feb. 1, with investigators saying there has been no sign of her.

The AP timeline traces last known moments to late January and early February in the Tucson area. It says Nancy Guthrie took an Uber to her family’s home for dinner on Jan. 31, and that a family member dropped her off at a Tucson-area home later that night, with her garage door opening and closing minutes afterward. On Feb. 1, the timeline says a doorbell camera was disconnected in the early hours and that the camera’s software detected movement, while investigators continued working to locate potentially lost or corrupted images in backend software. It also says a pacemaker app disconnected from her phone.

When family members checked on Nancy Guthrie after learning she did not attend church, they called 911 and authorities arrived and launched a search operation that included drones and dogs, the timeline says. By Monday, Feb. 2, authorities said they believed Guthrie was kidnapped, abducted or otherwise taken against her will.

As the investigation progressed, the timeline describes communications that the family and investigators treated as part of the search for Nancy Guthrie. It says a Tucson TV station received an email Monday night that appeared to be a ransom note, with deadlines set for 5 p.m. Thursday and again for Monday. A person familiar with the investigation later told The Associated Press that investigators found signs of forced entry at Nancy Guthrie’s home.

The timeline also highlights changes in the investigation’s evidence and public outreach. It says authorities allowed the family back on the property earlier in the week and then returned for a follow-up investigation, and that on Feb. 5 officials revealed DNA testing determined that blood found on the home’s front porch was Nancy Guthrie’s. On that same day, the FBI offered a $50,000 reward for information about Guthrie’s whereabouts.

In the days that followed, investigators and the family continued to issue appeals. The timeline says KOLD received an email tied to the case on Feb. 6 and forwarded it to federal investigators, and that investigators returned to Guthrie’s neighborhood to gather more evidence. On Feb. 10, the FBI said it recovered doorbell camera video showing an armed person tampering with a camera at Nancy Guthrie’s front door, including footage of the person covering a camera with a gloved hand and ripping out a plant to block the camera’s view.

The timeline says the FBI later increased the reward and tried to expand the evidence pool from residents across a wider area. On Feb. 12, investigators asked residents in a 2-mile (3.2-kilometer) radius of Nancy Guthrie’s home to share any camera footage and report suspicious activity in the month before she disappeared. That day, the FBI later doubled the reward to $100,000, seeking information that would lead to Nancy Guthrie or an arrest and conviction.

It also includes additional steps in the investigation involving local searches and a temporary detention. The AP timeline says the Pima County Sheriff’s Department detained a man for questioning during a traffic stop south of Tucson, released him, and said he told reporters he made deliveries in the Tucson area, and that the department searched a location in Rio Rico with the help of the FBI. The timeline says authorities later confirmed the man was released but did not say what led to the stop, while FBI agents and sheriff’s deputies knocked on doors and searched desert terrain around the homes of Nancy Guthrie and her oldest daughter, Annie Guthrie.

By late March, the timeline says Savannah Guthrie posted a family statement urging the public to review camera footage, notes, text messages and conversations that could matter, and it says the family acknowledged Nancy Guthrie might not be alive. On March 26, “Today” aired the first television interviews with Savannah Guthrie since the disappearance, and on April 6 she returned to the show again, telling viewers at the start of the program, “Here we go, ready or not,” and that it was good to be home.