Would this game be of any interest for fans of courtroom dramas/true crime? Me and my girlfriend love Dateline/48 hours/ 20-20, and we especially love seeing how the lawyers create stories out of the evidence to defend/prosecute. We've thought about how a lawyer videogame would be very cool. Does this pull it off? Also does it have full voice acting, that's sort of needed for us to play games together.
Yes, I'd say these games may be right up your alley, though note what you'd be getting into, such as some specifics for these two entries: they take place at the turn of the 20th century, and are based on the adventures of Sherlock Holmes. Expect more fantastic, "singular" crimes. In general, the mysteries and crimes are fairly elaborate and twisty in the Ace Attorney series. GAA seems to be a bit more grounded, but that's relatively speaking.
The gameplay is focused around the thrill of a turnabout; the thrill of turning an argument (and the court) upside down, and unravelling the mystery in each case in the process. You build logical links between the facts of the case and slowly poke holes at testimony and opposing arguments until you reach the truth. If what you're looking for is thrilling arguments and deducations using the courtroom setting, yes, absolutely, it's easy to recommend. But primarily the court is used solve the mystery in each episode.
Also, as mentioned above, the games do not feature full voice acting. Voice acting is mostly reserved for animated cutscenes. The games are basically novel-esque—nothing but text outside of the point and click segments.