Washer not spinning/draining - how to troubleshoot motor

Our washer recently stopped working. We went out to find it had a half-tub of water in it that did not drain. We tried moving the cycle about and it would only make a hum or droning sound. We went through a number of videos that showed how to replace all manner of parts, but nothing that really helped with troubleshooting the actual problem.

After watching a few videos, we noticed that most videos showed they could rotate the motor pulley freely. When we tried to turn it by hand in either direction we were not able to budge it at all.

The pump pulley can be rotated freely in either direction, and the transmission pulley in the center can be turned counter-clockwise and a short space clock-wise.

We are thinking that perhaps the motor is the issue and may need to be replaced. If anyone can share some ideas or confirm what we should be looking for we would very much appreciate the assistance.