Loading js from footer using wp enqueue script

Hello,
What do I need to add to this code to make the .js load from the footer?

//add scripts
public function enqueue_scripts() {
if ($this->enabled() == FALSE)
return;
$jsRoot = $this->pluginURLRoot . 'js/';
wp_enqueue_script('jquery');
wp_enqueue_script('wpfront-scroll-top', $jsRoot . 'wpfront-scroll-top.js', array('jquery'), self::VERSION);
$this->scriptLoaded = TRUE;
}

I think it would be
`$in_footer=true;

Thanks.