"Borderline" is a middling crime melodrama in which Charles Bronson, a stalwart officer of the U.S. Border Patrol in southern California, cracks down on illegal immigration. It seems to have stumbled into theaters after missing a more suitable dead-end engagement as a minor TV movie: The listless approach to Timely Social Problems would certainly be enhanced by wake-up calls from sponsors every 10 or 15 minutes.

The ordinary clandestine traffic in cheap labor -- earnestly identified as an ongoing problem and multi-million-dollar racket -- is meant to acquire melodramatic urgency when Bronson's fellow officer, Wilford Brimley, is murdered after stopping a suspicious produce truck late at night. Unfortunately, this fatality doesn't put any urgency or ingenuity into Jerrold Freedman's direction, which plods on to an equivocal denouement, allowing Bronson a big bust and a showdown with the killer while also permitting Mr. Big, some kind of disreputable businessman played by Michael Lerner, to evade justice due to "insufficient evidence."

Since Mr. Big's chief accomplice, a rancher played by Bert Remsen, gets off with a relatively light sentence, the killing of Brimley looks even more uncalled for in retrospect than it does at the time. It's rationalized by making the killer a Vietnam veteran gone bad: Ed Harris as a smugly expert, ice-blond mercenary out of the Marines.

This device may be considered hanging evidence that "Borderline" was hatched in the mental incubator of '70s television melodrama. Half the cops-and-robbers shows of the past decade would have been stumped for criminal motivation without the crutch of the renegade or psycho Vietnam vet, which became an irresistible cliche for Hollywood hacks disposed to confuse opportunism with social consciousness.

The Harris character is such a ruthless specimen that he also murders a boy caught in the line of fire when Brimley is gratuitously blasted. One of the illegal immigrants the killer was transporting across the border, this juvenile victim was bound for a mother employed as a domestic in San Diego. For a while it appears as if she's destined to become both informant and love interest to lawman Bronson, depicted as Very Lonely Guy away from the office. However, this thread of human interest ends up misused and discarded, obliging Freedman and co-writer Steve Kline to fabricate a climactic roundup which could only succeed because the bad guys conveniently throw caution to the wind and forget that Bronson has them under surveillance.

Bronson's character is identified as an ace tracker. But then, Harris keeps leaving incriminating soleprints all over the landscape. One of the fleeting, unpursued implications of the investigation is that Bronson is so resentful of the FBI that he prefers to conceal a clue that eventually proves decisive. It's difficult to see any point in this behavior, outside of movie-hero grandstanding.

As Bronson's facial wrinkles and creases accumulate, his inscrutable, heroic mug seems to be aging into craggy repose. His eyes are often crinkled into narrow slits -- suggesting that the star lacks enough vehicle to keep himself from nodding off at the wheel.