The suspect accused of firing three shots in the ABC10 building last week walked into a nearby elementary school office and asked to read to students days before, federal prosecutors said on Thursday.

Anibal Hernandez Santana is suspected of firing the shots in the news station building on Friday. He was arrested later that night by Sacramento police. He then posted bail the following day and was arrested by the FBI on federal charges.

In a Thursday detention hearing, a judge ruled that Hernandez Santana must stay in custody. Ahead of the hearing, federal prosecutors filed a motion to call the suspect a danger to the public. Wednesday night, his attorney filed a motion that he be released from jail with electronic monitoring and home detention. 

In a criminal complaint released Thursday, federal prosecutors said Hernandez Santana walked into an elementary school office, located just over two miles away from the ABC10 station, on Sept. 16. 

Prosecutors said Hernandez Santana was described by witnesses as wearing "military-looking pants, an army cap, and dark sunglasses." 

Attached to the criminal complaint is a photo from the school's surveillance cameras showing the suspect at the front gate just after 11:15 a.m. 

Inside the school's office, prosecutors said the employee he spoke with described his behavior as "weird" and "anxious." Prosecutors said he "frequently tapped on the counter and looked behind the employee, as if he was trying to see if anyone else was in the office." 

Hernandez Santana asked the employee if he could read to the children, but the employee said he could not, prosecutors said. The employee went on to tell him that he could volunteer, but would need to be cleared and speak with the school's office manager first. Prosecutors said Hernandez Santana insisted that he wanted to volunteer that day, but the employee told him it was not possible. 

In the criminal complaint, prosecutors said Hernandez Santana left a note for the office manager that said, "I would like to read to young students in my spare time." 

Hernandez Santana then left the campus at the employee's direction, prosecutors said.   

Prosecutors noted that some staff at the school were familiar with the suspect, saying his child was enrolled at the school two years ago and that Hernandez Santana temporarily taught an after-school Spanish class. They said school staff had not seen Hernandez Santana on campus "for a long time." 

After Friday's shooting at ABC10, staff members and teachers reported the incident to the FBI, with one employee saying Hernandez Santana appeared "very out of character," according to the criminal complaint. 

Prosecutors said the school staff was concerned for the school's safety if Hernandez Santana was out of custody. 

Prosecutors described the visit to the school as "both unusual and concerning," saying it was "consistent with pre-attack site surveillance, which is a recognizable indicator of an active shooter's planning and preparation activities." 

Sacramento City Unified School District said the incident occurred at Sutterville Elementary School. 

"The SCUSD Office of Safe Schools is aware of what happened and cooperating with law enforcement to determine what, if any, additional safety measures are needed for the Sutterville campus," the district said in a statement. "We recognize how frightening and concerning this news must be for families, which is why it's important to emphasize that there was never any direct threat to the Sutterville campus and nothing that warranted a call to law enforcement until well after the incident had occurred at the ABC 10 building. "

A weekly planner on Hernandez Santana's refrigerator had an entry to "Do the Next Scary Thing" on Friday, which suggested the "ABC10 shooting was only one step in a series of 'scary thing[s]' he had planned," prosecutors said. 

"Mr. Hernandez Santana is entitled to due process - he is innocent unless and until he is found otherwise," Mark Reichel, Hernandez Santana's lawyer, said in a statement on Monday.

Hernandez Santana is facing charges that include interfering with a radio communication station and possession and discharge of a firearm within a school zone. 

In a jailhouse interview with CBS Sacramento on Wednesday, he said that he's "not a violent man." 

The shooting happened a day after ABC's decision to suspend Jimmy Kimmel in response to comments about Charlie Kirk. A motive for the shooting remains under investigation.