By Sadie Gurman

Associated Press

EVERGREEN, Colo. — Ian Sullivan visits his daughter's grave on her birthday every year since a gunman burst into a crowded Colorado movie theater and shot the 6-year-old as she sat with her mother in the third row.

And every year he finds a birthday card, put there by the man who was with Veronica when Sullivan wishes he could have been: The police officer who carried the dying girl out of the theater in his arms.

Ian Sullivan stands on his deck reminiscing about the short life of his late six year old daughter Veronica, who was murdered in the 2012 Aurora movie theater shooting attack. (AP Image)

Sullivan's is one of the many horror stories that emerged from the Century 16 movie theater in Aurora, in suburban Denver, where James Holmes killed 12 people, including Veronica, and injured 70 others in July 2012.

Since then, survivors have been trying to reconstruct their lives, finding comfort in each other or seeking a higher purpose. A couple, wounded, got married. A father who lost his son became a gun control advocate. Others turned to faith.

Sullivan, 28, cut his ties to many of those who were closest to him before the attack, retreating to a home in Colorado's mountains. A lifeline has been the police officer whom he only knows by his first name, Mike.

The officer, Mike Hawkins, declined to comment, citing a judge's gag order barring anyone — defense attorneys, officers, prosecutors, witnesses — from talking to the news media about the case.

The officer still checks in on Sullivan with texts on the days that are the hardest — holidays, the birthday, Sullivan said.

"It's not so much all he was able to tell me, but more so the understanding that I was not alone," he said.

Veronica was born when Sullivan was 19. He said he had been far from a perfect teenager, getting into trouble with the law. He and Veronica's mother, Ashley Moser, weren't necessarily ready for the responsibility of parenting, he said.

But he was proud when he saw his newborn daughter. "It dramatically changed my life to have her," he said.

The couple divorced when Veronica was 3, but he still saw her regularly. He reveled in their time outdoors. A high point came in May 2012, when she caught her first fish, a trout. She gutted it herself.

One recent afternoon in a cramped, basement computer room where he spends much of his time these days, he flipped through photos of her. Veronica holding a fish by the lure. On a sandy beach. In a race car. On the first day of kindergarten. She flashes a toothless grin beneath her sandy blonde hair and Hello Kitty earrings.

Upstairs in his kitchen, he pushed a button on a photo frame she gave him a month before she was killed, and her voice filled the room.

"I love you, Daddy," she cooed, stumbling over a Father's Day greeting.

To keep Veronica's memory alive, he tries to do the things he used to do with her. He hikes. He skis. He works on cars — she used to hand him wrenches while he was under the chassis, he said.

He tries to stay busy to keep his mind from wandering into darker thoughts. It doesn't always work.

"I wasn't there to protect her," he said.

Sullivan's father, Robert Sullivan, said he encourages his son to talk and tries to listen. "What I notice is a very strong underlying anger and anguish that is going to be very difficult to overcome," he said. "It's going to forever alter him."

Just after midnight on July 20, 2012, Sullivan fell asleep at his Denver studio apartment, exhausted after returning from one of the long-haul routes he drove as a trucker. Two hours later, he was awakened by his phone.

A relative of his ex-wife told him he needed to get to the hospital. Veronica was dying.

He arrived too late to say goodbye to his daughter. Her mother was paralyzed in the attack.

Days later, he asked a victim's advocate to introduce him to the police officer who carried Veronica from the theater. They met at a police station in Aurora, not far from the shooting scene.

The officer told Sullivan that he, too, was a father. Sullivan said the officer told him that he thought he felt Veronica's heartbeat as he carried her from the theater. Sullivan realizes what the officer probably felt was his own pulse, his heart racing.

"The most comforting thing for me was knowing he was a father himself. To know that he picked her up the same way he picks up his own kids and he carried her the same way he carries his own kids," Sullivan said.

He told the officer the hardest part was feeling powerless and unable to protect his daughter.

"I know it took a lot out of him as well. I could see how much damage it had done to him," he said.

Getting the sporadic text messages and seeing the birthday cards reminds him that someone else out there — who was with Veronica when he couldn't be — is thinking about his pain.

"It helps to understand there's still someone there who actually cares," he said.

Copyright 2015 The Associated Press