suicide by cop
n. A form of suicide where people intentionally provoke police officers into shooting them.
It happens dozens of times each year during jittery hostage dramas and routine traffic stops: desperate people lure police officers into shooting them in a phenomenon known in law-enforcement circles as suicide by cop.
—Alan Feuer, “Drawing a Bead on a Baffling Endgame: Suicide by Cop,” The New York Times, June 21, 1998
Experts say it is every police officer's nightmare: a person with a death wish provoking police to pull the trigger.

They call it police-assisted suicide or suicide by cop, and they and say it's occurring with increasing frequency. Last week, it happened in Fresno when a man used a toy pistol to trick an officer into shooting him.
—Kimi Yoshino, “Officers stalked by growing phenomenon — 'police-assisted suicide',” Fresno Bee, June 21, 1998
1988 (earliest)
Haug was also worried about ''suicide by cop'' — the term used when a person intent on suicide intentionally starts a shoot-out that he knows he will lose.
—Bill Bryan, “Negotiator feared worst in standoff,” St. Louis Post-Dispatch, September 06, 1988