Prosecutors declined to file formal charges against the woman who caused a seven-hour standoff after reports of a shooting in Castaic — due to “insufficient evidence,” officials said Tuesday.

Linda Myers, 60, of Castaic, was booked on attempted murder charges last week after deputies heard shots fired through a door, according to Deputy Josh Stamsek of the Santa Clarita Valley Sheriff’s Station.

The District Attorney’s Office declined to file formal charges after “not being able to locate a firearm, a bullet strike mark or a shell casing,” according to a report obtained by KHTS.

Law enforcement originally responded to a “welfare check” at the Castaic Lake Senior Apartments around 4 p.m. Friday, said Deputy Joanna Warren, a LASD spokesperson, during an on-scene press conference.

See Related: Castaic Shooting, Barricade Suspect Charged With Attempted Murder

The initial call came from the LA County Department of Public Social Services after officials became concerned with the woman’s “bizarre and paranoid behavior,” according to Warren.

The responding units were aware Myers was a “habitual caller” to the Santa Clarita Valley Sheriff’s Station, and knocked on the door and announced they were with the Sheriff’s Department, reads the D.A. Report.

The deputies asked “Linda are you OK?” through the door, and a female voice sternly replied, “It’s Ms. Myers.”

When deputies realized Myers would not open the door, the deputies turned on their own personal recording audio/video device to document that she was safe and in her apartment, according to D.A. officials.

“After several seconds of silence deputies again called out to her by her first name,” reads the report. “After a few more seconds, deputies heard a gunshot coming from inside Ms. Myers apartment.”

Both deputies retreated believing they were taking gunfire and broadcasted “shots fired” and requested additional units, according to the D.A’s Office.

The 60-year-old woman then barricaded herself in the Castaic apartment for over seven hours, according to the LASD.

Deputies never saw anyone emerge from the apartment nor did they hear any further noise from the apartment, according to officials.

“At no time during this entire incident did deputies ever order Ms. Myers to exit her apartment or to open her door,” reads the report.

See Related: Deputies Detain Woman After Shots Fired At Castaic Lake Senior Apartments

The Sheriff’s Department brought in their tactical unit, the Special Enforcement Bureau (SEB), the Mental Evaluation Team (MET) and the Crisis Negotiation Team.

The standoff came to an end around 11 p.m., after SEB unit officials used a “flashbang” — a device which explodes with a loud noise and bright flash designed to disorient subjects but does not disperse projectiles — and gained entry to the apartment.

Myers was taken into custody and transported to a local hospital.

A search warrant was signed and detectives searched Myers’ apartment and the surrounding areas, according to the D.A.’s Office.

Detectives were not able to locate a firearm, a bullet strike mark, or a shell casing. The audio/video recording was reviewed and what sounds like a gunshot can be heard during the deputies’ attempts to check on the welfare of Myers.

Without physical evidence, however, there is insufficient evidence to prove this case beyond a reasonable doubt, said the D.A.’s Office

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