What to do if you know adult brother is abuses drugs and others?

I've just recently found out that my brother is stealing from my sickly ill mother, presently in the hospital, and abusing drugs-as confirmed by police as crack/cocaine. He lives with his 14 year old son, they don't get along at all, and has abusive tendencies. Ever since my mother was diagnosed with Stg 4 Cancer, with no recovery, he has been in a downward spiral. He confided in me that he is taking marijuana to offset the depression, however, as I visited the home to pick up a few things for my mom, he not only stole some of her clothing, jewelry and other family heirlooms, but I got so frustrated, maybe they were still in his room, I entered and found empty zip baggies with powder residue and small round burnt all around. Need help in making a drastic decision...call ACS, get him evicted, which means he will lose his job again, go to jail and devastate my mother even more, or should I wait, have a family intervention, because image matters to him, and wait it out?