Can not stop nohup process

I am trying to run a very complex statistical model that I expected to take a very long time, so I used

to run the process. However, I underestimated the length and it would take like 260+ days to complete so I want to cancel the process. I attempted using

ps aux |grep nohup

to get the PID, I get the following output:

\ 4920  0.0  0.0  14224   972 pts/15   S+   01:53   0:00 grep nohup

When I use kill -9 14224 I am told there is no process. So I used ps -ef | grep beast-2 as I do not remember the entire command I entered. Pulls up the following:

144039      1  0 Jul22 pts/12   00:00:00 /bin/sh /opt/anaconda3/bin/beast-2 -seed 777 -working -overwrite -instances 3 -threads 3 -beagle_SSE /home//XML/ST736_MTBD1.xml

I use kill -9 144039 and check again but the process is still running underneath a new PID. What can I do?