The disappearance of NBC journalist Savannah Guthrie’s mother spurred an urgent search, with law enforcement and family members asking the public for any information that could lead them to 84-year-old Nancy Guthrie.

When a kidnapping or suspected abduction is reported, investigators often say that time is the enemy. The first 24 to 72 hours after a kidnapping are widely considered the most critical window for safely rescuing a victim or determining what might have happened.

Here’s why those early hours matter so much, what law enforcement is doing behind the scenes, and what people often get wrong about missing persons cases.

Here’s why the first hours matter so much.

There’s no universal stopwatch that starts ticking the moment someone disappears, but investigators agree that the earliest hours offer the best chance for answers.