By CBS13 Staff

SACRAMENTO (CBS13) — The man accused of killing Natomas librarian Amber Clark in 2018 has pleaded not guilty by reason of insanity.

Ronald Seay appeared in court Wednesday. Police say he shot and killed Clark in an ambush-style attack as she sat in her car outside the North Natomas Library.

READ MORE: Police: Ronald Seay Has A Pattern Of Threatening Librarians, Starting In St. Louis

Clark had banned Seay from the library months earlier for harassing people.

Last June, Clark’s husband sued the Sacramento police and the Sacramento County District Attorney’s office over the release of tracing results from the weapon allegedly used in her killing. The DA’s office says federal law prohibits sharing that information about the weapon.

Her husband Kelly Clark said he was suing to force prosecutors to release it. He hoped to use the records to push for stricter gun control laws.

The weapon allegedly used was a gun legally purchased in Missouri.