Earlier this month at a Forbes healthcare summit, when asked by an audience member what he'd do differently, he said that he should "have raised prices higher," noting that his primary duty was to his shareholder.
In addition to giving a handful of interviews since the uproar began in September, he is also an active Twitter user, fielding questions from strangers and revealing his interests.
Shkreli is a Brooklyn native who attended Hunter College High School in Manhattan, though he did not graduate, a school spokesperson told ABC News. He has no college education listed on his LinkedIn page.
There are two patents, based on pharmaceutical substances for the treatment of neurological disorders, that list him among the multiple "inventors," patent records show.
One significant area of his interest is music, and that's also gotten him in the headlines in recent weeks.
Though he has not publicly confirmed it, it has been widely reported that Shkreli was the unidentified buyer who purchased the sole copy of a Wu-Tang Clan album for $2 million.
"The sale of Once Upon a Time in Shaolin was agreed upon in May, well before Martin Skhreli’s [sic] business practices came to light. We decided to give a significant portion of the proceeds to charity," the group's producer, Robert "RZA" Diggs, told Bloomberg Businessweek via email when the news was announced.
For his part, Shkreli has retweeted a number of articles about his alleged purchase, including the Bloomberg story that has a picture of him in the tweet.
When it comes to his passion for music, he isn't just a passive listener. Shkreli hosts frequent hours-long live stream sessions on YouTube where he alternates between answering questions from fans and serenading viewers with his guitar. Virtual chess games have also been featured.
According to Shkreli, he is finding an audience.
His dating habits, as he outlined in this Dec. 14 tweet, just days before his arrest, have also become fodder for his critics.
"50-100 date solicitations a day for me, the world's most eligible bachelor. Sorry, but you have to be a shareholder to meet me," Shkreli said in the tweet.