[20][12] Aslin gained some media attention for protesting his treatment by Nottinghamshire Police[21] in their investigation of his activities pursuant to the Terrorism Act "in the preparation to fight against Daesh" and possessing "articles for terrorist purposes in Iraq/Syria".

[23] Aslin has been critical of the international community's lack of support for the YPG,[24] of the Turkish occupation of parts of Rojava, and of the sale of British weapons to Turkey for attacks against the Kurds.

[43][44] On 27 May, the prosecutor's office completed its investigation[40] and announced charges on 6 June,[45] stating the following: "In the period from approximately December 2018 to April 2022 Shaun Pinner, Aiden John Mark Aslin, and Saadun Brahim acting deliberately by a group of persons by prior agreement as part of the armed forces of Ukraine, being on the territory of Donetsk People's Republic [DPR] in a time of war, being armed with firearms, took part in the preparation and military actions against the Armed Forces of the Donetsk People's Republic for the purpose of forcibly seizing and forcibly retaining power on the territory of DPR.”They were likewise accused of violating the "constitution" of the DPR by committing "terrorist acts, diversions, explosions, shelling from artillery, mortar [and] small arms" [against] "settlements, peaceful citizens, military of the Armed Forces of DPR," [and] "committing murders of the citizens of DPR, threatening of the civilians, who carried out their will during the referendum on May 11, 2014, which resulted in the forming of the state Donetsk People Republic.

On 9 June the Court found the trio guilty on all charges,[51] and stated that "[o]n the basis of the totality of crimes, Aslin Aiden, Pinner Sean and Saadun Brahim are finally given the death penalty as punishment.

"[52][51] On 5 July, Aslin's defence team filed an appeal, requesting the dismissal of the verdict due to lack of corpus delicti.

[55][10] Following his release, Aslin claimed in an interview that he was punched on the nose when his captors discovered that he was British and that he was tortured during his interrogation and his time in captivity.

[57] A spokesperson for Ukraine's foreign ministry said "Such public trials place the interests of propaganda above law and morality, and undermine the exchange mechanisms of war prisoners.

Since 2015, we have observed that the so-called judiciary within these self-contained republics have not complied with essential fair trial guarantees, such as public hearings, independence, impartiality of the courts and the right not to be compelled to testify.

"[59] On 12 June, Denis Pushilin, head of the DPR, appeared to rule out an executive pardon for the defendants, as "[t]hey came to Ukraine to kill civilians for money ...

Aslin believes this ban was placed in order to prevent re-use of his original passport captured by Russian authorities for a covert entry into EU.