Borderline is a 1950 American crime film noir directed by William A. Seiter and starring Fred MacMurray and Claire Trevor. It was filmed from late May to early July 1949 at Republic Studios.

Plot
Pete Ritchie (Raymond Burr) runs a narcotics smuggling operation to the USA from Mexico, which the Los Angeles Police Department and the US federal government have unsuccessfully tried to stop. Because of Ritchie’s careful operating procedures, US authorities haven’t even been able to find out the identities of his sources or customers and are desperate for a breakthrough. As a last resort, Madeleine Haley (Claire Trevor), an LAPD officer and former OSS operative, is sent undercover to Mexico to charm her way into Ritchie’s confidence.

Once there, Haley manages to establish contact with Ritchie’s gang, but is kidnapped by Johnny Macklin (Fred MacMurray), a federal agent posing as a hoodlum working for a rival of Ritchie’s and who also steals a load of Ritchie’s narcotics. Haley plays along and joins Macklin on a smuggling trip for the stolen narcotics, with Ritchie in hot pursuit.

Cast
Fred MacMurray as Johnny McEvoy, posing as Johnny Macklin
Claire Trevor as Madeleine Haley, posing as Gladys LaRue
Raymond Burr as Pete Ritchie
Jose Torvay as Miguel
Morris Ankrum as Bill Whittaker
Roy Roberts as Harvey Gumbin
Don Diamond as Deusik
Nacho Galindo as Porfirio
Pepe Hern as Pablo
Grazia Narciso as Porfirio’s Wife
Clifton Young as Suspect questioned by Whittaker
Charles Lane as Peterson, customs officer
Johnny Indrisano as Gumbin’s henchman
Chrispin Martin as Pepi, hotel clerk