Colorado Shooter James Holmes -- Rejected By 3 Women Before Massacre

James Holmes struck out with three different women on an adult sex website in the days before he shot 70 people in Colorado ... TMZ has learned.

We broke the story ... Holmes was an active member on AdultFriendFinder.com ... and now we've learned he reached out to multiple women before the movie theater attack.

TMZ spoke with three women who were contacted by Holmes since he opened his account on July 5 ... and each of the women tell us they turned down the killer's requests to meet up.

One of the women tells us ... Holmes wasn't aggressively seeking out sex -- in fact, she says he was "just looking to maybe chat ... nothing sexual."

The woman told us she rejected Holmes because she just wasn't into him.

Despite his innocent approach, Holmes made it clear on his profile he wasn't just looking for a friend -- in fact, he described himself as a guy looking for a "casual sex girl" and possibly group sex.