• On the ground now: Law enforcement searching for Nancy Guthrie is canvassing the Arizona neighborhood of her daughter Annie. The activity comes just hours after the FBI released surveillance footage from outside Nancy Guthrie’s front door taken the night she disappeared.

• Case’s biggest break so far: There’s been an uptick in calls to law enforcement since the doorbell camera footage — which shows a masked, armed person — was released today. Shortly after the footage was shared, “Today” show host Savannah Guthrie posted a new message from her family saying they believe their mother is still alive. Here’s what what law enforcement experts say stands out in the images.

• Tonight on CNN: Laura Coates will host a live one-hour special “The Search for Nancy Guthrie” on CNN & CNN All Access at 11 p.m. ET. Submit your questions about the investigation at CNN.com/AskLaura.

Ex-FBI agent breaks down Guthrie surveillance footage

Video released today by the FBI could hold the keys to solving the case of the disappearance of Nancy Guthrie. Former FBI special agent and CNN Senior Correspondent Josh Campbell breaks down what law enforcement could learn: