Mailing and Phone Notifications
If a group has a dozen contacts, or a few hundred, sending notification of a public event is an excellent way to make contact with people who have expressed interest in your work in the past. Mail an event flyer with the dates of remaining planning meetings.
A mailing can offer ways for volunteers to participate, and help your group grow. If you have had people in your community offer to help, now is the time to take them up on the offer. A mailing can put you back in touch with people that you haven't communicated with in a long time. Get them involved anew.
Using the phone shouldn't cost any money unless you have long distance numbers within driving range of a public event. Volunteers can share a phone list for calling people to planning meetings, and the public event.
Your group may want to begin using a 'phone tree', and thereby share the calls through a time tested method. A phone call from a volunteer is another way to get in contact with people who have been part of your group, or a project of your group in the past.
If your are mailing, calling, or using a combination of both methods. Now is a good time to reach out to others in your community who may share the desire to reform criminal justice policies. Invite them to plan with you at the very least, and perhaps they will attend a public event.