A Minnesota man accused of walking into a medical clinic and opening fire, killing one staff member and wounding four others, was indicted on a more serious charge of premeditated murder, and remained detained after a court appearance Monday.

A grand jury indicted Gregory Ulrich, 68, with one count of first-degree premeditated murder in the Feb. 9 shooting at the Allina Health Clinic in Buffalo, a small city about 40 miles (65 kilometers) northwest of Minneapolis. He also faces four counts of first-degree attempted murder in the attack.

He is also accused of setting off several pipe bombs at the clinic before eventually surrendering to law enforcement, and has been charged with discharging an explosive device.

Lindsay Overbay, a 37-year-old medical assistant, was killed in the shooting.

Read more: Minneapolis Star-Tribune