As reporters, we're not supposed to fall in love with those we write about -- no matter how soulful a set of eyes they flash at you.

So sue me.

I was working when I first laid eyes on Ace, visiting the Baltimore Animal Rescue and Care Shelter, known as BARCS, on a Saturday in October for an article about people who spend their weekends volunteering.

He was enjoying some outside time with a volunteer; later, I saw him again inside as I walked down a row of pens. He was in the first one, and unlike the rest of the inmates, he wasn't yelping.

Back home, even once my article was done, I kept seeing him -- in my head. I spent the week debating whether I really wanted another dog and all the responsibility that entails.

The Saturday that the article on volunteers appeared on the cover of The Sun's Today section -- with a photo of Ace and a BARCS volunteer -- I headed back to BARCS, my mind made up. I left with a partner.

What exactly did I come home with, though? Then, as now, it was anybody's guess. His official shelter documents called him a "hound mix." Several workers at the shelter called him a "shepherd mix." On the Web site, where he had been viewed 302 times, he'd been listed as a "Labrador mix."

That confusion -- and the possibility that it could be scientifically resolved with a newly available DNA test -- is what led Ace and me back to BARCS 18 months later. It was Step 1 of my quest to trace his roots, a journey that would later include sending his DNA to California for analysis in hopes of finding out what breeds are in him.

First, though, I wanted to see if the shelter knew more about him than it told me at the time I got him, which was basically that he was a 6-month-old stray.

BARCS Executive Director Jennifer Mead was amazed at how big Ace had become in 18 months, and she was as stumped as ever over what breeds he might be.

"We had him down as a hound mix, but I kept thinking shepherd mix, too. He had a hound look to him," she said. "But looking at him now ... I don't know that I see the hound. He's so tall, and his ears are so short compared to most of the hound ears, and he's got such a big block head -- as thick as a Rottweiler head.

"If I had to pick two, I would say Rottweiler and something else for a bigger size and a curled-up tail ... either shepherd or Akita."

When it came to Ace's history, it appeared that was going to be a guessing game as well.

Shelter records showed that he was a stray, found by someone who called animal control to come pick him up.

I asked Mead for the name of that someone, but she declined.

"I'm legally not allowed," she said. "But what I could do is call him and give him your number, and he could call you. Whether he'll know any more, I highly doubt it. He may have just found him that day and called us."

We left it at that, with Mead promising to let me know when she reached him.

Ace was one of the 5,000 to 6,000 dogs -- who are found on the streets, abused, neglected or given up by owners no longer able or willing to care for them -- that end up at BARCS each year. Another 3,000 a year wind up at the private, nonprofit Maryland Society for the Prevention of Cruelty to Animals in Baltimore and thousands more at other local and regional humane societies and rescue organizations.

At BARCS, where up to 98 percent of the 10,000 to 12,000 dogs and cats that came through each year were euthanized in the past, about half now get out -- either they are adopted or turned over to rescue groups, Mead said.