Shocked into action by police violence in Ferguson, Missouri, shares of TASER International (NASDAQ:AAXN) stock rocketed 75% between mid-July and mid-September of this year -- rising from a low of just $10.50 per share to as high as $18.43.

And yet, if you step back and look at the big picture, it turns out that much of these gains were merely recapturing ground lost earlier in the year. For 2014 as a whole, TASER shares are up a much more modest 3.8%. Why?

As so often in the stock market, the answer really comes down to just two things: promise and performance -- not necessarily in that order.

TASR Total Return Price Chart

TASR Total Return Price data by YCharts.

TASER's performance is a problem
From a performance perspective, it's not hard to see why TASER's share price trended downward for most of the first half of this year. GAAP earnings at TASER were off more than 6% in the first half of 2014, as compared to the first half of 2013. Free cash flow at the company has dropped by more than half, according to data from S&P Capital IQ.

True, sales are up 17% at TASER over H1 2013 levels. But so far, this sales growth has not translated into greater profits. Perhaps worse for investors who've relied upon analyst predictions that TASER will produce 30% annualized earnings growth over the next five years, so far, the company seems to be falling far short of that mark.

Promises, promises
And yet, even as earnings and free cash flow erode, we've seen a remarkable rebound in TASER International's share price these past two months. The reason can be summed up in just three words: police body cameras.

AXON Body Camera. Photo: TASER International.

Ever since the story of Michael Brown's shooting death in Ferguson broke, pundits have speculated that had the officer involved in the shooting been wearing a body camera on his uniform, he might have been less likely to use force in that incident -- perhaps saving a life. This speculation has fueled increased interest in the AXON series of on-body cameras that TASER produces, and the service it provides for storing and searching the video produced by these body cameras.

The pundits are right to wonder about that. And investors are right to wonder if the new attention being given to body cameras could mark an inflection point for TASER.

In 2013, a TASER-sponsored study provided strong evidence suggesting that when police officers wear on-body cameras, they are much less likely to resort to use of force of any kind -- with incidents of use of force declining by as much as 59%. With public pressure mounting for police to reduce use of force in encounters with the public, that's a big incentive for police departments to begin buying, and deploying, more AXON systems.

Meanwhile, TASER is burning no daylight taking advantage of the increased attention for its product. Already this year, it has raised prices on both of the most popular of its AXON models -- and raised the price of its service as well. As recently as February, we pegged AXON body and AXON flex cameras at price points of $299 and $499, respectively. But go to TASER's website today, and you'll see the prices have already been hiked by $100 on each.

The increase in monthly charges for the service, where TASER stores data from AXON cameras on behalf of its police clients, is even more dramatic -- from $10 per month to $15 per month. (Sure, from one perspective that looks like just a $5 increase. But it's an increase of $60 across the course of a year, and a 50% bump in price from just a few months ago.)

The upshot for investors
Now, it remains to be seen whether these increases in price will translate into faster revenue growth, and bigger profits for TASER International. But that would be a logical result. And as you can see in the chart that led off this piece, investors appear to be betting that's precisely what will happen -- that TASER's free cash flow line will bounce right back up and begin tracking the surge in price per share when TASER next reports earnings.

If they're right, TASER International shares that currently sell for close to 47 times earnings, and appear to be priced out of all proportion to the 30% earnings growth rate (that TASER's currently not even coming close to hitting), may not be quite as expensive as they look.

If history is any guide, TASER International should report Q3 earnings sometime in late October, or early November at the latest.

Rich Smith has no position in any stocks mentioned. The Motley Fool has no position in any of the stocks mentioned. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.