diff --git a/capture.js b/capture.js
index 5d2a1b8..da33f67 100644
--- a/capture.js
+++ b/capture.js
@@ -3,6 +3,9 @@ var stream = require('stream');
 var logger = require('./logger');
 
 
+var runningCams = {};
+
+
 function runCommand(command, displayName, callback)
 {
 	var wait = function()
@@ -83,11 +86,23 @@ module.exports =
 
 	start: function(camId, cam, now)
 	{
+		if (runningCams[camId] === true)
+			return false;
+
+
+		runningCams[camId] = true;
+
 		var processor = new (require('./processor-' + cam.processor))(camId, cam, now);
 		var duringCommandsDone = false;
 		var queueAfterCommand = false;
 
 
+		var unlockCam = function()
+		{
+			runningCams[camId] = false;
+		};
+
+
 		runCommands(cam.before, 'before', function()
 		{
 			processor.on('start', function()
@@ -97,7 +112,7 @@ module.exports =
 					// Check if the processor has already finished and the
 					// 'after' commands should be run immediately.
 					if (queueAfterCommand)
-						runCommands(cam.after, 'after', function() { });
+						runCommands(cam.after, 'after', unlockCam);
 					else
 						duringCommandsDone = true;
 				});
@@ -109,12 +124,14 @@ module.exports =
 				// to be less than the duration of the 'during' commands,
 				// queue it up.
 				if (duringCommandsDone)
-					runCommands(cam.after, 'after', function() { });
+					runCommands(cam.after, 'after', unlockCam);
 				else
 					queueAfterCommand = true;
 			});
 
 			processor.run();
 		});
+
+		return true;
 	}
 };
\ No newline at end of file
diff --git a/index.js b/index.js
index 2263a48..04ca470 100644
--- a/index.js
+++ b/index.js
@@ -102,17 +102,24 @@ app.get('/capture', function(req, res)
 	{
 		var now = moment();
 		var cams = [];
+		var alreadyRunning = [];
 
 		for (var camId in config.cams)
 		{
 			if (config.cams.hasOwnProperty(camId))
 			{
-				cams.push(camId);
-				capture.start(camId, config.cams[camId], now);
+				if (capture.start(camId, config.cams[camId], now))
+					cams.push(camId);
+				else
+					alreadyRunning.push(camId);
 			}
 		}
 
-		logger.info('Started capture for: ' + cams.join(', '));
+		if (cams.length > 0)
+			logger.info('Started capture for: ' + cams.join(', '));
+
+		if (alreadyRunning.length > 0)
+			logger.info('Capture already running for: ' + alreadyRunning.join(', '));
 
 		res.send(JSON.stringify(cams));
 	}
@@ -131,9 +138,12 @@ app.get('/capture/:camId', function(req, res)
 
 		if (config.cams.hasOwnProperty(camId))
 		{
-			capture.start(camId, config.cams[camId], moment());
+			if (capture.start(camId, config.cams[camId], moment()))
+				logger.info('Started capture for: ' + camId);
+			else
+				logger.info('Capture already running for: ' + camId);
+
 
-			logger.info('Started capture for: ' + camId);
 			res.send(JSON.stringify([camId]));
 		}
 		else