LOS ANGELES (CNS) — A man accused of fatally striking a 70-year-old nurse in the head in an unprovoked attack at a downtown bus stop pleaded not guilty Wednesday to a murder charge.

Kerry Bell, 48, is charged in the Jan. 13 attack on Sandra Shells, who was waiting to catch a bus to her job at Los Angeles County-USC Medical Center when she was struck at about 5:15 a.m. at a bus stop at Vignes Street and Cesar Chavez Avenue, near Union Station.

The woman fell, striking her head on the ground.

She died Jan. 16 at the hospital where she had worked for 38 years.

Bell was arrested about 1 1/2 hours after the attack and has been behind bars since then. He was being held in lieu of $2 million bail, and was scheduled to return to court May 26, when a date will be set for a hearing to determine if there is enough evidence for him to stand trial.

In January, LAC+USC Medical Center announced the creation of a memorial fund to benefit the Shells' family. The Sandra Shells Memorial Fund will also help "other families who have been affected by or have fallen victim to violence," according to the medical center.

Hospital officials noted that Shells would often arrive early in the morning before her shift so she could sit in the locker room and read her Bible.

"LAC+USC Medical Center family is overwhelmed by the outpouring of love and support received in the wake of Nurse Sandra Shells' passing," according to a hospital statement. "We are grateful to those who have paid tribute to Ms. Shells by extending their condolences, sending flower arrangements, and posting heartfelt messages on social media. We appreciate your sentiments and we thank you for sharing in our sadness."

Donations to the memorial fund can be made online at lacusdfoundation.org.