Welcome, @SummerHouse! If you do carry on listening, you may have more questions, so feel free to ask here. The Archers has been on the air continuously since 1st January 1951 and there's still one original cast member going strong (she's a centenarian now
) so there's a lot of history to get to grips with. You can get stuck in without knowing much of that, though which is what the scriptwriters appear to be doing a lot of the time, after all.
Re criminal offences at Brookfield - Josh came close when the police questioned him after one of his vehicles was involved in something dodgy/outright criminal and his paperwork was found wanting. I think the police dropped that in the end, though.
David was definitely in court back in the 80s/90s for killing a badger and burying the body. Matt Crawford saw him and reported it to the police. David was consumed with rage against the badgers for repeatedly infecting the Brookfield dairy herd with TB (he assumed).
The Grundys are definitely known to the police. Back in the early 2000s, Ed was convicted of taking Will's car without permission and crashing it, causing serious injuries to Emma's legs (never mentioned now) - she got compensation from the Criminal Injuries Fund (if that's what it's called) and it paid for her wedding to Will.
There was also a storyline involving selling dodgy meat a while back. Eddie was the one in the sights of Borsetshire Police then. Can't remember if it got to court. He may have dobbed someone else in to get off the hook himself.
Ed must have come close to prosecution again over that business of dumping chemicals, but I can't remember how it all ended.
In days of yore when Joe and Eddie were running Grange Farm as a proper farm, they were always skating close to the wind on matters of agricultural regulations over sheep dipping and so on. Whether any of those breaches ended up in prosecution I can't remember now. The SWs used them as the 'bad farmer' example to compare and contrast with the 'good farmers' at Brookfield, Bridge Farm and Home Farm (also Mike Tucker and Neil Carter). There used to always be one bad farmer to help with slotting in the Min of Ag propaganda. It was Walter Gabriel originally, but they turned him into a comic character instead as he got older.
Was Clarrie prosecuted for the E Coli incident, or was that just Bridge Farm? She lost her job for a bit after being identified as the cause of the contaminated ice cream.