Oh honey, I am so very sorry. I hope he enters the rehab.
While it's hard to think about, I have listened to testimonies of some hard drug users. They did one short stint in rehab after another. It was not until they had done some very real time in jail until they came out clean. You know what, many of these people are now productive members of society willing to share their stories to help another person.
When there is a warrant for an arrest, it takes a bit of time to get it faxed over to the correct police dept, then they put it on a list. They may show up, or they may not, depending on their own work load. Eventually he will get caught. While it hurts, you will know he is being fed and clean.
I hope he takes the opportunity, but you have to know you have done everything in your power for him. Now you pray.
Tight, tight hugs. Sending you much love!