From the U.S. department of Health Human Services:
What does “suicide contagion” mean, and what can be done to prevent it?
Suicide contagion is the exposure to suicide or suicidal behaviors within one’s family, one’s peer group, or through media reports of suicide and can result in an increase in suicide and suicidal behaviors. Direct and indirect exposure to suicidal behavior has been shown to precede an increase in suicidal behavior in persons at risk for suicide, especially in adolescents and young adults.
The risk for suicide contagion as a result of media reporting can be minimized by factual and concise media reports of suicide. Reports of suicide should not be repetitive, as prolonged exposure can increase the likelihood of suicide contagion. Suicide is the result of many complex factors; therefore media coverage should not report oversimplified explanations such as recent negative life events or acute stressors. Reports should not divulge detailed descriptions of the method used to avoid possible duplication. Reports should not glorify the victim and should not imply that suicide was effective in achieving a personal goal such as gaining media attention.
I would imagine that media reports should also not imply that the mass killing shooter was effective in achieving a personal goal such as gaining media attention. But the media can’t seem to help doing that when making a mass shooter famous is useful in demanding gun control or a crack down on discussion of the Great Replacement Theory.