Senator Clinton and investor Jack Lindenbaum are learning the hard way that supposedly sure things in life are often no more than a mirage.

Mr. Lindenbaum’s discovery is especially painful. A few years back, he invested most of his life savings, about $700,000, in the shares of a stun gun maker, Taser International, after his broker assured him that it was “a sure thing,” he writes in an e-mail. Mr. Lindenbaum, now 77, notes: “I was an idiot. I have lost almost two-thirds of my money. Is there any hope for me with Taser?”

Judging from the current stock price, $11.27, down from its 2005 high of $32.49, Wall Street doesn’t seem very enthusiastic. There is one exception, however. Taser, whose shares over the years have frequently ballooned and then swooned, has found a new champion in Jefferies & Co., which recently recommended the stock in a report to clients featuring its 10 favorite companies for the next 12 months.

Over the next three to five years, Taser’s per-share earnings should grow 40% a year on an annual sales gain of between 30% to 35%, a Jefferies analyst, Matthew McKay, said.

Mr. McKay further tells me he expects sales to rocket to about $500 million in five years, from last year’s $100 million volume. He pegs this year’s per-share net at $0.38 a share, up from $0.23 last year, and sees another gain to $0.55 in 2009.

Mr. McKay notes that Taser is generating interest from larger cities that want to move to full deployment, where all officers except those sitting behind a desk will carry the weapon. He believes that this year and next the majority of America law enforcement agencies will move to full Taser deployment. Currently, the company has penetrated about one-third of American law enforcement.

Internationally, Mr. McKay expects law enforcement revenue to gain significantly as multiple countries move into the procurement phase; penetration is presently a miniscule 2% abroad.

Last July, Taser introduced a new consumer model, the C2, which carries a $350 price tag (versus the X-26, the law enforcement model, which goes for $850). To date, the C2 is showing early signs of healthy growth, Mr. McKay observes, and he estimates that the company sold 20,000 units of this model during the December quarter without advertising and with limited retail channels.

Looking ahead, he believes earnings-per-share upside, a return on invested capital in excess of 50%, and diminishing legal risks should lead to a healthy expansion of its forward P/E multiple. Yet another plus, as Mr. McKay sees it: a solid balance sheet, characterized by a lot of cash ($51 million) and no debt.

But the stock’s roller-coaster performance in recent years — characterized by frequent sharp declines and marked by unusually wide spreads between the yearly highs and lows — bears out some analysts’ skepticism and underscores the substantial danger in owning Taser shares. Last year, for example, the stock traded between $7.44 and $19.36. A much larger range, between $5.31 and $32.49, took place in 2005, with shares closing out the year at $6.96.

Some pros, belittling the inclusion of Taser in the Jefferies report, argue that the brokerage firm is way off base in its Taser pitch, given the following potholes:

• A host of lawsuits confronting the company on wrongful death and injury

• A series of disappointments, with management repeatedly stubbing its toe against expected orders, sales, and earnings

• The prospect that future domestic and international growth will fall short of expectations

• A highly inflated stock valuation, with the shares sporting a ritzy price-earnings multiple of nearly 50

• Stepped-up negative press reports on the potential hazards stemming from the use of stun guns

The skeptics are by no means alone in their bearish appraisal of Taser’s prospects, as evidenced by a huge and rising short interest (a bet the stock price will fall) of 20.1 million shares. That’s up about 40% from 14.6 million shares the prior month, despite the stock’s roughly 40% drop from its 52-week high of $19.36.

Jefferies shot back against its critics: “The shorts are crazy,” Mr. McKay tells me. He sees lofty growth prospects ahead and a near doubling of the stock price to $20 over the next 12 months.

One final note Mr. Lindenbaum: You might want to see a lawyer.

dandordan@aol.com