he explained to me that some people are like beacons to an abuser...we tend to be too trusting of all people. it's ok to trust people it's just that we are so "open" to too many people.
red flags-i can give you examples: a person that seems to be controlling of others. a person that tells us what they did to get back at a person or we witness it ourselves. they seem to be proud of their response (vindictiveness). a very self-centered person, narcisistic. a person that is quick to get angry at an infraction they see is pointed to them-like getting angry in a traffic situation. at first these characteristics are not aimed necessarily at us. that comes later.
let me give you a very plain example. i had a very good male friend. when i moved into a new home i had the palms of my hands on the wall in the living room. he slapped my hand and said, don't put your hands on the wall cause you'll make a mark on it. because i knew that i was of worth by then i promptly told him i paid for the wall and i could put my hands all over it if i wanted to and to never touch me like that again!
later he wanted to date me. i said NO. i did not give him an explanation. there was no point because an abuser can always justify their actions. they are never wrong in their eyes.
this is a generalized version of what i learned. i hope this info helps give you some input but a T can help you much better than my examples.