04/05/2009 05:12 am ET Updated May 25, 2011

Report: Chris Brown Punched Rihanna, Threatened to Kill Her

A detective's notes from the scene of the alleged Rihanna assault reportedly reveal disturbing details about what happened between the singer and her boyfriend Chris Brown in the early hours of Feb. 8.

According to FOX 11 in Los Angeles, which claims to have obtained the notes from a search warrant in the case, Rihanna, 21, read a lengthy text message from a woman on Brown's phone, which led to an argument. Brown -- who has a standing court date Thursday -- allegedly tried to force his girlfriend out of the Lamborghini, and hit her head against the passenger window.

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