Q: remove web police virus

It's not a virus.

1. Force Safari to quit by following these instructions: OS X: How to quit an unresponsive application using Force Quit.
2. Hold a Shift key while launching Safari again.

If that does not fix the problem:

1. Force Safari to quit again.
2. Disconnect from the Internet by selecting Wi-Fi "off" in the Mac's menu bar, or disconnecting its Ethernet cable if you're not using wireless.
3. Launch Safari again by holding a Shift key.
   • No pages will be able to load since you're not connected to the Internet.
4. Select the Safari menu > Preferences > General, and review your home page selection.
5. Select Remove All Website Data... > Remove Now.
   • After you reconnect to the Internet, you will need to sign in again with all websites that require authentication (such as this one).
6. Turn Wi-Fi back on again or reconnect your Ethernet cable.

You'll be back in business.

In an abundance of caution, consider the following additional actions. They are not required to eliminate the scam webpage but you should review them to determine certain Safari settings have not been unexpectedly altered.

1. Open Safari's Preferences... and select Extensions. Uninstall any Extensions that you are not certain you require by clicking the Uninstall button.
   • If you are not sure what to uninstall, uninstall all of them. None are required for normal operation.
2. Select the Privacy pane. Verify "Block cookies and other website data" is configured the way you expect. If you are uncertain, choose "From third parties and advertisers".

Sorry I omitted that step.

Replace step 5 with

5. Select the Privacy pane > Remove All Website Data... > Remove Now.