I guess you're talking about *[The Thirteenth Floor][1]* from 1999. It had a very similar storyline to what you have described. It's a great movie, I must say.

>In late 1990's Los Angeles, Hannon Fuller (Armin Mueller-Stahl) is the owner of a multi-billion dollar computer enterprise and the inventor of a newly completed virtual reality simulation (VR) of 1937 Los Angeles. When Fuller is murdered just as he begins premature testing of the system, his friend and protégé Douglas Hall (Craig Bierko) finds himself the primary suspect, and begins to doubt his own innocence.
>
>Between questioning by LAPD Detective Larry McBain (Dennis Haysbert), Hall meets Jane Fuller (Gretchen Mol), who he is surprised to learn is Fuller's estranged daughter. Hall develops a romance with Jane, who we soon find out is attempting to shut down the new VR system. When a local bartender who witnessed a meeting between Hall and Fuller on the night of the murder is himself found murdered, Hall is imprisoned. He is soon released though, after Jane provides him with an alibi.


  [1]: https://www.imdb.com/title/tt0139809/