When Army Sgt. Paul Costello returned home to West Chester from an 18-month tour in Iraq in 2006, he "went on vacation for three months," he said, laughing.

"I was so burnt out," he said. "I was just so happy to be home."

But his initial relief was short-lived, he said. He grew depressed and suicidal. He began drinking almost every day - "I was trying to go out and have as much fun as possible," Costello, 28, said. "I felt I had missed out on so much."

He worked 80-hour weeks to keep his mind off the nightmares and the insomnia, the memories of 18 months in war-torn Ramadi, "which was and still is one of the worst places in Iraq," he said. He started taking antidepressants, only to abruptly stop, triggering even more severe depression.

And, then, just months after returning from Iraq, Costello woke up in the hospital facing a burglary charge. Incensed over a fight with an ex-girlfriend, he got drunk, blacked out, showed up at her apartment, and picked a fight with her boyfriend, breaking a door in the process, he said. It was his first criminal offense.

Costello had spent two years waiting to be sentenced and a third on probation when Chester County launched its Veterans Court program in 2011, one of about a dozen counties in the state, including Philadelphia, Montgomery, and Delaware, to establish a separate court to deal with offenders whose experience in combat zones may have contributed to their criminal behavior.

Costello was its first participant, and since then the county has accepted 15 other veterans into the program. Four have graduated.

The program generally admits nonviolent offenders - a murder, rape, or even a firearms charge, for example, will render them ineligible for Veterans Court.

"That's a selling point for the public," said Pat Carmody, the prosecutor assigned to Veterans Court. "We want to assure them we're not putting dangerous people back on the street."

But the county does try to treat crimes involving veterans on a case-by-case basis, said Judge Thomas Gavin, a former captain in the Marine Corps and a Vietnam War veteran who presides over the special court.

"It's not an assembly-line approach," he said. "We're not looking to have a strict set of parameters. When it's black and white, the gray gets missed."

Under the system, eligible veterans can be released into an intensive probationary program that combines mental health or drug treatment with frequent check-ins with judges and probation officers. They're called in for random drug tests and required, as necessary, to undergo electronic monitoring.

"These programs are intensive - the defendant has to buy into it," Gavin said. "I say you don't get a drug problem in a day, and it doesn't go away in a day."

Veterans spend as much time as necessary in the program. Army Sgt. Melania Curtis-Stafford, who entered in 2010 after two DUI arrests in one week, said she was initially reluctant to join the program, even spending an additional 13 days in jail after a "setback" during her probation.

"I was so frustrated - here I am, 41 years old, and these people have my life under their thumb," she said.

A finance and accounting soldier based in Baghdad, she dealt with a bombing at her base in the Green Zone and returned home reeling from the effects of her tour as well as the deaths of her father and grandmother. The Veterans Court found her a live-in substance-abuse program for veterans in Allentown. Now sober, she hopes to graduate early from the program.

Curtis-Stafford said many veterans avoid getting help for post-traumatic stress disorder and related issues because they don't want to seem weak.

"When you get home, you're feeling fine. You're feeling like the strongest living human being," she said. "Then you start feeling suicidal and wondering what is wrong with you. My dad would always tell me, 'Don't be weak,' and I stuffed everything inside."

Jennifer Lopez, deputy chief of the county's adult probation department, said the county researched programs in Anchorage, Alaska, and Buffalo and surveyed 60 veterans in the county prison before launching the program.

"All we're doing with Veterans Court is capitalizing on military culture," she said. "We have four veterans working in the court and a judge who was a veteran himself."

Lopez said the court was not designed to cut veterans an easy break, but rather to direct them toward services designed to decrease their risk of reoffending.

"They work hard for this break," she said.

Three years since entering Veterans Court, Costello said he was working hard, too. He's on his way to a business degree at West Chester University and is thinking about graduate school. But returning veterans, he said, should not hesitate, as he did, to get help after a tour of duty.

"There's this macho attitude, like, 'Oh, I went through this, but I don't have to deal with it,' " he said. "But one day it might just come out like it happened with me."

Contact Aubrey Whelan at 610-313-8112, awhelan@philly.com, or follow on Twitter at @aubreyjwhelan.