Antipsychotic drugs and a suicide letter addressed to his parents were discovered in the apartment of the shooter responsible for the mass tragedy in Manhattan this week, as reported by WPIX in New York.

Upon searching Shane Tamura’s Las Vegas studio apartment, NYPD investigators uncovered several prescription drugs, 100 rounds of 9mm ammunition, a tripod for the rifle utilized in the attack, and an empty revolver storage box, officials stated on Wednesday.

Several prescription bottles for antipsychotic, antiepileptic, and anti-inflammatory drugs were also recovered, according to an NYPD spokesperson.

Tamura, 27, also left behind a suicide note to his parents, saying in part, “I love you, mama. I’m sorry.”

The suicide notes left by Tamura referred to a person named Rick, identified as his boss at Horseshoe Las Vegas, where he worked as a security guard, according to police.

“I’m sorry, Rick,” the note found in the shooter’s wallet said.

Authorities revealed that Rick had sold Tamura the AR-15 rifle used in the shootings for $1,400, along with the BMW that facilitated his journey from Nevada to New York City.

Rick, whose last name is being withheld, has not been charged with any crimes.

Four individuals lost their lives when Tamura commenced shooting at approximately 7 p.m. on Monday in the lobby and the 33rd floor of a Park Avenue tower, which contains offices for the NFL, Blackstone, and Rudin Management, officials noted.

The deceased include NYPD Officer Didarul Islam, Blackstone executive Wesley LePatner, security guard Aland Etienne, and Julia Hyman, with NFL employee Craig Clementi sustaining injuries, stated NFL Commissioner Roger Goodell.

Tamura, a former high school football player from Las Vegas, shot himself in the chest and died at the scene, police said. Authorities said Tamura left behind three suicide notes blaming the NFL for his brain injury.

The three-page handwritten suicide note was found folded inside the shooter’s wallet and written on preprinted planner-style paper, including a page labeled “My Daily Affirmations” and another with “Plan, Pause, Reflect, and Flourish” printed in the center, police said.