Years ago I watched a b/w film biopic of Krupa on afternoon TV and was left with the general impression that the drummer's career was ruined after being busted for marijuana. It was a Hollywood movie so he made a come-back, of course.

How much of this was true?

I can't remember all the details because I was pretty stoned at the time.

It was probably the one starring Sal Mineo, who looked about 12 years old for most of his life. I remember the arrest looked terribly traumatic in the movie, but I believe he was actually acquitted of the charges. All of the big bands were in decline at about the same time, so it would be hard to blame the demise of Krupa's band on the arrest, even if it had the appearance of cause and effect.

Thank you, Pinhedz.

I just read the Wiki story, which is more than a little misleading. First, it neglects to say that Krupa finally beat the rap (the most serious charge was contributing to the deliquency of a minor). Here's the final outcome, from an article written at the time:

"On February 15th, 1944, almost a year after the abortive case had begun,
John Pateakos, in Army uniform (and no-longer a so-called wayward minor
as the press had made out), testified as follows in juvenile court:

"I lied," he said. He swore that he had been coached in his testimony
by narcotics agents. He said he had never been asked by Gene Krupa to
get marijuana from Krupa's room.

On May 31st, 1944, the California District Court of Appeals, in a
thumping decision, overruled the jury's verdict and set Gene Krupa free.

Thus, under the laws of our land and in all fairness to the great
drummer, it is high time to halt the innuendos and the sneers. It is
also high time to halt any similar attacks and smears on the great
players of our time.

All hail, Gene Krupa, Bang it out eight to the bar. And we know
it's you, and not the weed, that's doing the magnificent drumming."

The Wiki also suggests that Krupa only got back to work by rejoining Benny Goodman, neglecting to mention that by the end of WW-II, Krupa was leading a big band that even had a full string section--practically a symphony orchestra.