The first series of "Luther" aired in 2010 and received positive reviews from critics, getting an average of 5.9 million viewers per episode. In August 2010, the BBC announced that it had commissioned a second series for 2011. Filming started in late September/early October 2010. Originally planned to be broadcast as two two-hour episodes, it was shown as four one-hour episodes. The first episode was shown on BBC One on 14 June 2011. In August 2011, the BBC One controller announced that a third series had been commissioned. Filming of the four-episode series started in November 2012. Sienna Guillory was cast as Luther's new love interest. Other guest stars included Lucian Msamati and Ned Dennehy. The third series began airing on 2 July 2013 and concluded on 23 July. On 19 November 2014, it was announced that a two-episode special would be aired on the BBC in 2015. Filming began in March 2015 and ended April 2015. BBC Home Entertainment later confirmed that the Region 1 version of the Series 4 DVD would be released on 15 December 2015, coinciding with the air date of the fourth series. On 24 October 2015, BBC One confirmed via their Facebook page that series 4 of "Luther" would air in December 2015 on BBC One. In November 2015, it was announced that Luther was confirmed to air in the United States on BBC America for a three-hour one-night event on 17 December 2015. The first episode of the fourth series aired on BBC One on 15 December 2015. The BBC announced a fifth series composed of four episodes on 12 June 2017. Filming started in early 2018. Ruth Wilson was confirmed to be returning as Alice Morgan for series five. Series 5 directed by Jamie Payne premiered on 1 January 2019, and was broadcast over consecutive nights through to 4 January. Creator Neil Cross has said that Luther is influenced by both Sherlock Holmes and Columbo; the nature of Luther's intellect and its application to solving crimes is comparable to Holmes's, whereas the show's use of the inverted detective format was inspired by Columbo. The first series was filmed in and around London, England, and produced by BBC Drama Productions. Brian Kirk, Sam Miller and Stefan Schwartz each directed two episodes and show creator Neil Cross wrote all six of the episodes. Leila Kirkpatrick was the line producer for the entire program and Katie Swinden was the producer for a number of episodes. Tim Fleming provided cinematography for two episodes. Katie Weiland and Victoria Boydell were involved in film editing, with Weiland editing two episodes.