It's happened to every leader. You hire a new employee. You have high hopes that he or she will be a solid contributor to your organization. But things don't work out that way. A few months later, you are forced to let this new person go. You wonder if there was something you missed in the interview process.

You probably didn't miss it, says Larry Weidel, coach, senior national sales director at Primerica Financial Services, and author of the new book Serial Winner. "Here's the truth: We almost never miss the red flags," he says. "Our warning detectors go off. But we choose to overlook the problems we see. No candidate is perfect, we tell ourselves. And that's true. Every recruiting effort is an equation, weighing pros and cons."

Sometimes you need to ignore those gut feelings and give candidates you're not sure about a chance to prove themselves. Other times those gut feelings are a certain sign that you should run the other way. How can you tell which is which? By keeping a careful eye out for the warning signs that you should never overlook, Weidel says. They may be subtle. But if you see signs of any of the following three behaviors, the smart move is to pass the candidate by.

1. Hesitation.

"Making decisions is how things get done," Weidel says. "People who can't make decisions don't get things done."

You should never hire a hesitater no matter how good his or her skills. So it's important to spot hesitaters in the interview process. What do they look like? "People who dream without doing--who talk a lot about the things they would like to do and not much about the things they've actually done," Weidel says. Candidates who focus mostly on plans and intentions may have been unable to make the decisions that were needed to reach their goals. 

"Instead, look for people who are able to tell you about the specific things they have done to get the things they've wanted in life," he adds. "Ask them about the big goals they have achieved." Candidates who have not yet made good on their own goals are unlikely to meet any for your organization, either.

2. Self-doubt.

Watch out for candidates who use self-limiting language, Weidel advises. This includes phrases such as "I wasn't prepared for...," "I hadn't learned enough yet to...," or "I don't have a background in..."

These people believe they are incapable of achievement, he says. "That will keep them from making progress, even when others are leading the way. Instead, watch for candidates who speak with confidence--not arrogance--about their achievements and capabilities."

3. Placing blame.

Candidates who blame anyone or anything other than themselves for their failures have little sense of personal accountability and are likely to let you down, Weidel says. "When the going gets tough--when an obstacle crops up in a project, or when a client is upset about the handling of an account--they are likely to throw their hands in the air, point a finger, and look to somebody else to figure out a path forward."

How do you spot these people? As Weidel notes, it's a rare job candidate who's dumb enough to say something like "I was fired from my last job because my boss was a total jerk." Instead, listen for the more subtle signs that someone is a blamer.

To bring these out, ask candidates about their past bosses and past companies, and challenges they faced. Watch out for people who imply that a former boss was incompetent, even if only by tone of voice or facial expression. Also look out for those who allude to poor corporate leadership at a previous position, or those who keep referring to the economy to explain why they or their teams were unable to perform.

On the other hand, "people with a strong sense of personal accountability and the ability to adjust to shifting circumstances will talk more about specific problems and how they contributed to solutions than they will about bad bosses, bad corporate leadership, or the bad economy," Weidel says.

4. Stagnation.

"People who don't make career progress in a reasonable amount of time often suffer from a crucial character flaw--lack of interest in learning or growing," Weidel warns. "You know your industry. You are probably a fairly good judge of how long somebody survives at a particular level before being either moved up or moved out. If somebody seemed to languish in a position, dig in. Make sure you have a clear, reasonable answer why the candidate didn't make faster progress."

There could be a perfectly good explanation, he adds. "If someone took time off from their career for personal reasons (such as raising a baby or caring for a sick relative), they might make slower career progress. Also, if someone was pursuing a big goal outside of work--training for an Ironman, finishing a college degree at night, starting a nonprofit, etc.--they may have devoted less energy to career advancement for that period. But those big goals are a sign that they're interested in growing and achieving."

Beyond that, he says, "you should be looking for people who exhibit a natural curiosity and desire for new and bigger challenges. Ask them what they've done to improve in past positions. Ask them how they grew their contributions over time. And ask them what they want to be doing in five years. It's a question everybody asks, but many interviewers don't pay attention to the answer. Winning team members will have a specific answer that shows their desire for growth."