Whowatch is an interactive who-like program that displays information about the users currently logged on to the machine. In addition to standard information (login name,tty, host, user's process), the type of the connection (telnet or ssh) is shown. We can toggle display between the users commands or idle times. We can watch the process tree, navigate in it and send INT  and KILL signals.

[email protected]:~/Desktop$ sudo apt-get install whowatch
[email protected]:~/Desktop$ whowatch

We can also use whowatch to send signal to one PID and choose number of signal,
for example we can choose 9 to kill one process (PID). 



This is a good utility to try..