Bash Script: Kill Process by Time

I need a crontab that run every 2 hours or less that kill httpd process by specific time, detail: 1. get a list of all httpd process that is start 2 hours ago and no running but remain in process list... (make the time a variable so i can change it later) 2. after get the list, delete each process.. note - search process condition: a. more than 2 hours b. currently no running c. is a httpd process