Isabel Chavelo Gutierrez, 53, broke into the woman's rural home armed with a knife and attacked her.
But in the midst of the rape he complained he wasn't feeling well and "stopped having sex with her so he could rest," the Corpus Christi Caller reported citing the local sheriff's office.
The registered sex offender continued to fondle her, however, then rolled over and died.
The woman initially thought he had passed out drunk because she smelled alcohol on his breath. She fled her home in her car and called her daughter for help.
Investigators believe Gutierrez died of a heart attack after riding his bicycle two miles to the woman's home on a hot summer day but are awaiting the results of an autopsy.
He was on parole for sex crimes including indecency with a child in 1986 and had been released from prison in 2008.
Read more: http://www.news.com.au/world/texas-man-d...6075387037