A biopsy device includes a first cannula driver connected to a first cannula and a second cannula driver connected to a second cannula. The first cannula driver has a first rack member and a flange. The second cannula driver has a second rack member. A drive assembly has a linear motor drive, a transmission assembly, a switching motor drive, and an electrical controller circuit. The electrical controller circuit is configured to execute program instructions to selectively operate the linear motor drive and the switching motor drive. The transmission assembly has a gear assembly drivably coupled to the switching motor drive and configured to releasably engage at least one of the first rack member of the first cannula driver and the second rack member of the second cannula driver. A coupler member is connected to the linear motor drive, and is configured to engage the flange of the first cannula driver.