Frank says:

There were 45 men in the jail cell, the toilet and shower had never been cleaned, the temperature was 110 degrees so you couldn't sleep night or day, there were roaches in the oatmeal, sadistic guards, and everything that was nice. -- Zappa 1969 interview. This had happened during the days of Studio Z in Cucamonga (1963). Frank was released on bail (his father took out a bank loan to pay for it). Frank had been busted for "conspiracy to commit pornography," after making a silly recording of suggestive sexual sounds (giggling edited out) for someone who had asked him to provide a "special" tape recording for a stag night. That someone turned out to be Detective Willis of the San Bernadino Vice Squad. Their conversation was recorded by a hidden microphone and this was used as evidence at Zappa's trial.