How about "gun-grabbing criminal coddler"?
The problem I have with that is it tends to water down the emphasis on coddling criminals - and THAT is what these people are all about.
If you look at the sphere of influence these people move in, it includes anti-guns, anti-police, liberal courts, reduced jail sentences, and anti-death penalty. The one common thread throughout is “these poor little criminals.”
I wish I could find it, but some idiot that was a vice-president of Handgun Control back in the 80’s said something to the effect of, “I don't care if a woman wakes up at three AM with somebody trying to rape her, she still shouldn't kill him. The penalty for rape is not death.” That really sums up the entire gun control movement and it's purposes.