Law & Order: UK is one of the best crime dramas on television, on either side of the Atlantic. As the series returns to BBC America tonight (9 PM ET/PT), I sat down with LOUK's lead writer and a dear friend of mine, Emilia di Girolamo, to talk about what's ahead - like the previously announced cast changes - and how she and the talented team have injected new life into the Law & Order franchise.

Getting the basic question out of the way: how did you come to be involved with the show? What made you interested in it?

I was a huge fan of the mothership and in particular SVU, so when I found out halfway through a meeting for something else that Kudos were making LOUK, I literally begged them to consider me! They didn’t have a slot at the time but halfway through season one when they needed another writer, my name came up. Chris Chibnall read my spec and got me in for a meeting. He couldn’t help but notice my boundless enthusiasm for the show and geeky L&O knowledge. I was in Hastings Aquarium with my daughter when I got the call from my agent – I think I may have freaked out a few of the fishes with my excitement! I got the job and wrote "Hidden"– the rest is history!

You started out with the show practically from the beginning - you wrote the second episode of series two. What's it been like to rise through the ranks and grow with the program?

It’s been amazing and far beyond my expectations. There was only one slot available in season two but I hoped they would call me back for seasons three and four. When I was asked to join the core team and write three episodes I think I literally leapt for joy! I ended up writing four episodes and my episodes "Broken" and "ID" got to open the seasons - "ID" worldwide except in the UK - which was amazing.

To get promoted to Lead Writer and Co-Producer for seasons five and six was the icing on the cake. I’ve written five episodes this time round and had a fantastic time. I’m a little sad to say goodbye to the show after almost three years but I’ve written ten episodes, said everything I have to say and it’s time to let someone else have a bite of the cherry.

I’m hugely excited about writing my own series which I’m doing right now for Clerkenwell Films and ITV1 as well as developing a whole slate of other projects with UK broadcasters.

One of the problems with the US audience is that a lot of people seem to think the UK edition is just re-using the US scripts. So, for those of us who aren't familiar, can you talk about how you choose which episodes to adapt, and what the actual process is for adapting them?

Keeping with Dick Wolf’s ‘ripped from the headlines’ lynchpin, I always choose stories which feel relevant to a UK audience. If it couldn’t happen here or wouldn’t happen here then it’s not for our show. I also love the stories which feel morally complex. I like to have something to get my teeth stuck into and debate rather than just a murder mystery.

For me there would be no joy in changing the locations and changing ‘janitor’ to ‘care taker’! I take my adaptations as far away as humanly possible from the originals. In fact it’s rare I keep the same killer and if I do you can bet there’s a huge twist or two in there and plenty of unexpected turns along the way.

If you really want to analyze it – watch [the original Law & Order episode] "Promises to Keep" and "ID" or "Killerz" and "Broken." It’s not just the legal system that gets a makeover. The cases are radically different in terms of investigation and the actual offences.

How much do you change? We've heard how the cases are adapted to fit the British legal system, but I'm really more fascinated with how the writing staff is able to create unique arcs for the UK characters within the scripts. It seems to break the Law & Order formula of sacrificing character for plot.

In terms of character arcs, season five takes our regulars on huge emotional journeys. We deliberately chose episodes that would help us do that. All I can say is watch season five – we go far deeper into character than we ever have before and it feels a very natural evolution.

I want to ask you about "Survivor" - you had to follow "Confession," which was the adaptation of "Bad Faith," one of the best-known L&O episodes. As a writer, is it at all intimidating to follow a notable episode?

Well we don’t necessarily write them in sequence; in fact I wrote "Survivor" before Terry Cafolla wrote "Confession"! But we always knew those eps would be in the series, if not the exact running order. I think they are both such different episodes and it never crossed my mind to be intimidated.

I love "Bad Faith" and Terry and I certainly had a bit of a spat over it! We loved so many of the same episodes and our ‘wanna write’ lists were often virtually identical. In fact I think in the end he may have traded me "Killerz" (which became "Broken") and a Starbucks for "Bad Faith"!

The show's also very sharp with its continuity. As the head writer, how do you keep all the details in order?

We have an amazing script editor who does that for us! We also have the razor-sharp mind of Mr. Bradley Walsh (who stars as DS Ronnie Brooks; pictured above in the upcoming episode "Safe") to pull us up when we get it wrong! He’s very hot on his character continuity. When I’m working on a new season I just get really immersed in it – it’s hard not to hold on to the detail when you’re literally living and breathing a show.

You have a really impressive cast - not at all who I would have expected, but they all fit their roles perfectly. That in mind, from a writing standpoint, what was it like to go through the first set of cast changes? How do you craft a proper exit story for a major character like James Steel or George Castle?

I wasn’t involved in crafting the exit for either of those characters – that task fell upon the writer working on the exit episode ("Skeletons"), but doing so is an immensely difficult and daunting task. I was thrilled though to create our new regulars for season five and am very excited to see how the audience react to them. [Actors Ben Daniels and Bill Paterson] are hard acts to follow but hopefully we’ve got the new characters and the casting spot on. New actors certainly bring a new and exciting dynamic to the show which I don’t think is bad thing. As sad as it is to lose original cast members, I love a challenge and creating new characters for a show like LOUK is a terrific challenge.

Speaking of the cast, how closely do you work with the actors? Is it a more collaborative environment or do you prefer they stick closely to the scripts?

We have a table read for each episode where the cast get to discuss any suggestions or changes to script but after that they stick pretty closely to it. As writers we really value their input – they know their characters better than anyone so if a scene or a line doesn’t feel right, it’s important to make sure that’s sorted before we shoot. But as writers and producers we also know where the characters are going and the bigger picture so it’s important to also be true to our vision for the season.

Are there any missed opportunities - episodes you wanted to adapt but couldn't, or plotlines/moments that ended up being cut?

I love the episode "Captive." It’s got fantastic twists and turns and is incredibly morally complex. It was on my list to adapt but in the end we felt it would be too challenging to a UK audience. Other than that I got to adapt all my favourite episodes. Oh, and there was "Bad Faith" of course – but Terry won that fight!

So we know what great TV you turn out. What shows do you watch?

I watch TV voraciously – mainly US shows. My all time favorites are The Sopranos, The Wire, Dexter, The West Wing, Six Feet Under – the writing in all of them is brilliant and innovative. I’ve found True Blood, 24, Prison Break and Breaking Bad really entertaining. My light relief is 30 Rock and Curb Your Enthusiasm – they both make me laugh so hard and all crime writers need to kick back now and then!

I loved The Killing (the Danish original – not the remake) and can’t wait for nextseason. I would urge US crime fans to check it out.  It’s truly brilliant in so many ways and hugely addictive.

There’s less UK TV that’s inspired me unfortunately. I love Doctor Who and Torchwood for pure entertainment value. I would secretly love to write an episode of Doctor Who and give it my spin. It’s been a very long time since a UK crime show has had any impact on me. Prime Suspect and Cracker in their day of course. There was a great UK series called Conviction a few years back.

Other favourite UK shows past and present are the utterly brilliant Misfits, The Crimson Petal & The White, Afterlife, Rebus, Funland, and North Square. I wish I could cite a few more but I think UK TV needs to work a lot harder to match the US.

My thanks to Emilia for a fantastic interview! Follow her on Twitter (@EmiliaDG). The fifth-series US premiere of Law & Order: UK is tonight on BBC America, and stay tuned after it airs for my review.