From the Epoch Times article - Search warrants are being executed at places associated with Cole, officials said. The overall investigation is active and additional charges may be brought.

Now, it doesn’t say if the additional charges are against the same suspect or if there are more suspects. Link to article - https://www.theepochtimes.com/us/fbi-arrests-person-in-investigation-into-bombs-placed-in-dc-on-eve-of-jan-6-post-5953624?utm_source=ref_share&utm_campaign=copy