OKLAHOMA CITY - A suspect is in custody for Oklahoma City's latest homicide.

Robert Carmack, 27, was arrested and is accused of killing a man Friday at a home near SW 50 Street and Shartel Avenue, but investigators are still trying to determine a motive.

Witnesses told police that Carmack, their neighbor, came into the house and opened fire, but his victim did not even live there. Billy Gannon, 36, was tattooing a woman who lives at home just before 5 p.m. Friday

Her unfinished tattoo will forever be a stark reminder of a few harrowing moments. She told News 9 she did not know Gannon well, and just met him about three weeks earlier.

“He comes over here all the time,” she said. “He had done a tattoo on my friend, so he drew something up for me and I liked it. The way he had it drawn up, it was really nice.”

Gannon was inking the name of the woman’s daughter “Avah” across the back of her right hand, and it was supposed to be completed with a beating heart. Instead, the woman felt the beating of Gannon's last seconds of life.

“He had a hold of my hand when he was getting shot, so every shot, every time he got hit it was squeezing, like he was squeezing me like a heartbeat. It was crazy,” she said.

A day later, her hand was still shaking from fear. She told News 9 that Carmack, who lives two houses away, burst into the room and started shooting. She could not say know why, but said Carmack has pulled a gun on his own family members before.

Carmack did plead guilty to unlawfully carrying a weapon in 2013. Right now, there is no indication that Carmack knew his victim, and police told Gannon's sister they do not believe shooting was gang or drug related.

Gannon’s sister told News 9 they recently lost both of their parents, so the family is hoping for community support to properly lay her brother to rest. She created a GoFundMe page Saturday after learning of Gannon’s death.

If you have any information about a possible motive for this shooting, call police.