Ray Buso, who has represented Wallace in those cases, did not return phone calls from The Salem News on Wednesday and yesterday.
Wallace is also awaiting trial on charges in New Hampshire. Buso told a judge earlier this year that Wallace was fearful of serving his sentence in Massachusetts and was trying to find a way to serve his time in New Hampshire.
The plea hearing has been delayed five times since last March, in part because of those efforts.
Courts reporter Julie Manganis can be reached at 978-338-2521, via email at email@example.com or on Twitter @SNJulieManganis.