Blog Del Narco[1] is one such underground source. Of course, some accuse it of falling short of journalistic standards because it filters almost nothing, and so has often been used as a de facto PR outlet for numerous cartels. Even so, one of its founders is believed to have been murdered in 2013, and the other was forced to leave Mexico permanently.
Very committed group working with material to translate into English to spread knowledge about the goings on in the large scope of the country. Many different regions / players. Just a suggestion.
I'm curious, what risk(s) do you mean? If you mean NSFW and disturbing violence, you're right, and I apologize to anyone who didn't get that - I assumed given the topic it would be self evident.
Also I second your endorsement of Borderland Beat, that's what I actually read as a non-Spanish speaker.
From what I'd seen posted on the Borderland Beat forums on a semi-regular basis BDN gets injection type viruses. They're a target in that regard because of their site having vulnerabilities.
That's the main concern of why I don't visit, but in a secondary category is I've seen several instances where the Borderland Beat crew fact-check and note that BDN has recycled old material / videos under the guise of new information. I don't see that as helpful so I keep that under advisement.
Might not be a surprise but Breitbart apparently is staffing a Cartel / Mexico Crime crew to a decent extent and I have given them a look here and there. Viable sources are viable, and that's a dangerous as all get out sector to be in, so if they can get facts reported, I'll check them out / cross-reference with Borderland Beat.
Similar situation with Narco News[1] (though I know nothing of its journalistic standards)... I had a friend who was working for them in Mexico about 15 years ago, and he ended up quitting and leaving the country after a co-worker was killed.
[1]http://www.blogdelnarco.com/