"America's Most Wanted" host John Walsh says America's spiraling crime stats, and criminals getting smarter are just 2 reasons why his famous show is returning to FOX.

John and his son, Callahan Walsh, are hosting the 'AMW' reboot, and they joined us Monday on "TMZ Live" to discuss how crime has changed since the show's initial heyday in the '90s and early 2000s.

It was way back in 1988 when 'AMW' premiered on FOX and John tells us crime is so bad these days, honchos at the FBI told him they wanted his show to return, so he could help bust criminals ... particularly in areas the agency considers "lawless."

Another change since the OG 'AMW' ... John says advances in technology are making it easier to find criminals -- but he points out some of that technology also gives the bad guys more tools to break laws, and get away with it.

There are plenty of new criminals for John and Callahan to track down on their reboot ... but they tell us their program will also take a crack at solving some cold cases too.

No one understands the importance of staying on cases like that more than the Walsh family -- John points out he waited 27 years for the police files that eventually helped solve his 6-year-old son Adam's 1981 abduction and murder.

The new 'AMW' premieres tonight at 8 PM ET on FOX, and the Walshes tell us they plan to keep fighting crime in Adam's honor.

Following the premiere of 'AMW,' be sure to stick around and tune into "TMZ Investigates: Obsessed and Dangerous: Hollywood’s Stalker Crisis" -- the start of a weekly series that hits FOX Monday at 9/8c.