RIVERVIEW — Early Saturday morning, Cristy Vasilakos got into an argument with her boyfriend.

Daniel Robertson had been drinking, she said, and was angry. She kicked him out of her apartment at the Grand Oaks in Riverview just before 6 a.m.

But he came storming back, she said. Demanding to be let in, he smashed two of her windows and banged on her front door. At some point, the fight moved outside to the sidewalk.

The noise awoke neighbors, including Vickie Rock, who was staying the night at her boyfriend's apartment upstairs.

Rock, 50, of Riverview, came outside armed with a .45-caliber handgun and saw Robertson beating Vasilakos with a metal object, said Hillsborough sheriff's spokesman Larry McKinnon.

When Rock tried to intercede, Robertson turned on her. Rock suffered several facial injuries before firing at least one round and striking Robertson, McKinnon said.

Robertson, 56, staggered away and was found dead in the parking lot a few minutes later by deputies.

As detectives wrapped up their investigation Saturday afternoon, Vasilakos, 40, stood barefoot outside her apartment door, smoking a cigarette and trying to make sense of what happened.

"He was hurting me," she said, fresh scratches visible on her cheek and shoulder. "I don't know what he was going through. I'm just really upset."

Robertson had anger issues, she said, but had never attacked her before. The two met in church more than eight years ago and had only recently started dating. She works as a security guard and has three children, who were not home at the time of the shooting. He worked on cellphone towers, she said, and did prison ministry. He lived a few apartment buildings away from where he died.

"He wasn't a bad guy, which is why it is hard to believe this happened," she said. "I really thought he was a mentor for me."

Robertson was charged with possessing drug paraphernalia in 2005 and failure to appear in court in 2006, state records show. The disposition of those cases was unclear Saturday. Rock has no criminal record in Florida.

Vasilakos had never met Rock before. She hadn't realized Rock had a gun until it went off. Even then, she didn't know how serious Robertson's injuries were. "I had no idea he was dying," she said.

She understands why Rock fired, though.

"She was doing her part," Vasilakos said. "I feel like she stood her ground. He was on top of her when she shot him."

No charges were filed Saturday. Since 2005, Florida has had a "stand your ground" law, which allows the use of lethal force with no duty to retreat if a person reasonably believes his or her life is in danger.

A woman answered the door at Rock's house on a quiet street in Riverview just after 5 p.m. Saturday. She opened the door just wide enough for a large dog to stick its nose out and for her to peer out of one eye — the other was swollen shut. She said she had no comment.

Investigators will work with the Hillsborough County State Attorney's Office to determine whether any charges will be filed.

Times reporter Elisabeth Parker and Times researcher Natalie Watson contributed to this report.