The disgraced actor was arrested on 29 December (15) after police officers raided his home in Sunland, California after receiving a tip-off and allegedly discovered "thousands" of inappropriate images on his personal devices, which were seized.
He was taken into custody following the bust by the Los Angeles Police Department's Internet Crimes Against Children Task Force unit and released after posting $20,000 (£14,000) bail.
Mark has remained off social media and has not publicly spoken since the incident until Sunday (06Mar16), more than two months later, when he posted a selfie with his friends Cee and Jessica on Twitter and Instagram. They appeared to be at a party.
In the caption, he writes, "Always a good time with @ceearsali and @jessicasavano #homies."
Prior to the snap, he last posted on social media on Christmas Day (25Dec15) when he shared a picture of him kissing the head of a squirrel. He has previously been pictured running errands and attending the gym in California since his arrest.
Mark filmed a role in Gods and Secrets alongside Kellan Lutz before the controversy, with the movie's director Adi Shankar vowing to stand by the actor until the allegations are proved to be true.
He told TheWrap.com, "I'm going to wait for all the facts to arrive and if in fact these allegations are true, I will immediately take action, which includes removing his scenes from the project."
Mark's friend Hudson Wells also spoke out about the actor's arrest, insisting he is "devastated" and "ruined" by the incident. Hudson told In Touch, "I don't know whether he's guilty of what he's been charged with, but I think there's got to be some sort of substance to the allegations. I don't think the police would have gone to his house and taken him to jail if he was completely innocent."
He adds Mark, who played Noah 'Puck' Puckerman on smash hit show Glee, "could have made wiser decisions."