PHOENIX - Phoenix Police say a 27-year-old man beat his girlfriend to death with a tire iron behind a strip mall near Bethany Home Road and 35th Avenue.
The 26-year-old woman died on scene, according to police.
Police have identified the man as Luis Madrigal and the woman as Monique Gemino.
Officials say they were responding to a domestic violence call in a parking lot when they found Gemino incapacitated from her injuries.
Madrigal was still present with the tire lug wrench in his hands, and would not comply with the officers' orders, authorities say. Officers say they fired five stun bags at the man before they could take him into custody.
Police say Madrigal's relationship with Gemino deteriorated weeks before her death, and that the argument was over the woman's alleged affair with another man. Madrigal said she admitted to the affair, and struck her with the tire iron in a rage, according to the police report.
Reports show Madrigal approached a bystander after the assault, telling him, "Hey bro, I just beat the s*** out of my girlfriend, and make sure they send plenty of cops." The suspect said he wanted police to shoot him.
Madrigal scratched the word "cheater" on Gemino's car hood so police would know why he killed her, officials say.