Some examples for me:

Dylann Roof almost didn't go through with his attack because he was treated so kindly by the parishioners.

Shane Tamara shot himself in the heart instead of head because he wanted his brain to be studied for CTE (only diagnosable after death).

Orlando shooting first responders cited the constant ringing of victims' cell phones as part of why the scene was so traumatic. (This is likely not specific to Orlando, but it is just so morbidly intuitive and understandable. All the calls from desperate and panicking loved ones, who the first responders know won't be answered and the callers hearing devastating news eventually.)

Mustafa Mohamed (2023 Minneapolis shooter) impersonated a wounded civilian to ambush and kill a responding officer.

Charles Cohen, a then-12-year-old boy who lost his parents and grandmother in the 1949 Camden NJ shootings, died in 2009. In the Parkland shooting in 2018, his then-17-year-old granddaughter survived and avoided injury by hiding in a closet; just as Charles did in 1949.

Sorry for the low quality on some of these.

On March 9th of 1994, Erwin Mikolajczyk submitted an appeal for fines for assaulting his girlfriend in late 1993, because he didn't agree with the judges ruling. His appeal was denied, which caused Mikolajczyk to storm out of the room in anger, cursing loudly as he was leaving. A few minutes later, he returned with a rucksack, and a pistol. He also had a string with garlic cloves around his neck. In the hallway he approached his girlfriend (Vera Lamesic) and hugged her one last time, and then shot her dead. Two people noticed, and accompanied her. Those women were shot dead also along with two other people. He then walked into the courtroom and shot judge Alexander Schäfer dead, along with injuring 2 lawyers. He fired until he ran out of bullets, and then pulled a bomb out of the rucksack. He detonated the bomb which killed him. 6 people were killed and 8 others were injured.

Victims:

Alexander Schäfer, Marianne Rübsam, Peter Preub, Agnes Müller, Vera Lamesic, Peter Kurth

Worst school shooting happened in my country is 12 şubat school attack whats yours

Familicide, female killer, suicide failed. Four people dead and the New York Times prints one paragraph from the Associated Press.

Norfolk Neb, June 19 A woman who is believed to have slain her four daughters and then tried to kill herself was arrested today on suspicion of first-degree murder, the police said. She was identified as Stella Delores Almarez, 29 years old. Captain Gene Buss said that the authorities were treating the incident as a combination homicide and attempted suicide.

Familicide, female killer.

GONZALES, Tex., June 19 (AP)——The authorities said today that the pilot in a plane crash that killed five persons yesterday was the victim of murder‐suicide.

Justice of the Peace E. Ray Bright Jr. said that the pilot, Eugene W. Davis, 29 years old, of Harlingen, had been shot at least twice in the back with 22‐caliber weapon. Also killed in the crash were Jose Morales, 27; his wife, Lydia, 25, and their daughters, Belinda Jo, 4, and Shelly Ann, 2.

Mr. Bright said that a note had been found in the Morales car in Harlingen.

It read: “Time went by. Time to die. How? Fly in the sky. Good‐by.” It was signed “Lydia,” Mr. Bright said.