Comment by gpm

Gluing a few stories together (links included below where I'm not citing to your link) it seems like:

~2012 he was caught selling MDMA and marijuana, and went to prison

~end or 2015 or start of 2016 he was released on probation

[Edit: Added entry] December 2016 police responding to a domestic violence call enter his apartment to make contact with the alleged victim, and discover U-47700 (a synthetic opioid) https://www.courts.nh.gov/sites/g/files/ehbemt471/files/docu...

April 2017 the police find traces of carfentanil while executing a search warrant at his place - plausibly but not provably linked to some recent carfentanil deaths - and police announce they are searching for him. https://www.cbsnews.com/boston/news/man-wanted-suspected-let...

May 2017 he ends up back in prison.

Aug 2017 he pleads guilty to possession of U47700 (a synthetic opioid) with intent to distribute https://www.wmur.com/article/defense-plans-appeal-of-search-...

Oct 2017 he's sentenced to 15-30 years on the above charge, he has not been charged with possessing the carfentanil (yet) despite the apparent evidence https://www.wmur.com/article/man-facing-carfentanil-charge-r...

The articles aren't clear on this, but given his own recounting I assume that a suspended sentence for Marijuana was un-suspended as a result of the new charges and he is serving that sentence first, or concurrently.