Deputies who visited Elliot Rodger’s apartment last month in response to reports that he had posted threatening videos online acted in accordance with state law and department policy, a report released by the Santa Barbara County Sheriff’s Office on Thursday afternoon stated.

The report revealed that deputies did not watch the videos or check whether Rodger owned firearms at the time of the “check the welfare” call on April 30. The Sheriff’s Office was first alerted to the videos by a staff member at the County Alcohol, Drug and Mental Health Service’s hotline who was contacted by Rodger’s mother and someone claiming to be his friend.

The department is in the midst of an internal investigation examining its handling of the welfare check and whether anything could have been done to prevent Rodger’s killing spree Friday, which left six victims dead and 13 injured.

“This is one of the most complex investigations in the history of the Santa Barbara County Sheriff’s Office,” the statement said.

Four deputies, a university police officer and a dispatcher-in-training responded to the welfare call at 10:17 p.m. While these types of calls typically only require two deputies, the report said two other deputies who were familiar with Rodger’s petty theft case against his roommate joined the two deputies on call at the time.

According to the statement, the deputies interviewed Rodger outside his apartment and found him to be “shy, timid and polite.”

“Rodger told them he was having trouble fitting in socially in Isla Vista and the videos were merely a way of expressing himself,” the statement said.

The deputies said they did not have reason to believe Rodger was an immediate threat and no cause to put him under an involuntary mental hold. Rodger’s mother was called at the scene, and Rodger was given information on various local services he could contact if he needed help.

On the night of the killings, Rodger emailed his 137-page manifesto to several people including his mother, father and therapist at 9:18 p.m., a minute after he uploaded his final video to YouTube. Gunshots were first reported at 9:27 p.m.

The therapist first saw the email at 10:00 p.m. and contacted the police at 10:11 p.m., the report said. The police were not aware of Rodger’s “retribution” video or his manifesto until 10:26 p.m., a full hour after the rampage had begun. A family friend of the Rodgers said his parents rushed to Isla Vista immediately after seeing the email but arrived too late to prevent the tragedy, according to NBC News.