Editor's note: Joshua Coleman is co-chairman of the Council on Contemporary Families and a psychologist specializing in parent-adult child relationships. His most recent book is "When Parents Hurt: Compassionate Strategies When You and Your Grown Child Don't Get Along."
(CNN) -- What if he were your kid? You wouldn't raise that kind of kid. You'd know the signs and get help. You'd have spotted it early on and gotten help for him right away. You would've seen the warnings and acted before it became the national tragedy that it did. Good parents don't raise those kinds of kids.
But, what if you're a good parent and you didn't see the signs and you did raise that kind of kid, or at least some kid like that?
You knew something was wrong, but you didn't know what to do. So you told yourself, it's a phase. Lots of kids these days talk about death, have pictures of skulls, watch violent video games, take drugs and write things that they call poetry; it's not like any poetry you'd ever read, but what do you know? You're not a shrink. Maybe it will get better.
You're not the Loughners, your kid hasn't been accused of killing anyone, but something's wrong with your kid and you don't know what it is and you're scared. You don't have a lot of money or you just lost your insurance, so you took your son to the county hospital because lately, he's been so angry all the time that you don't know what's wrong with him.
And the psychiatrist at the county ER tells you that he's schizophrenic and should be on anti-psychotic medication and they'd like to keep him for two weeks on an involuntary hold.
So they keep him for two weeks on an involuntary hold, but because of the cutbacks in county mental health services, there's no place to refer him when the hold expires, except back to you. And now that he's on medication, he's much calmer and no longer seems to be a threat to others. Crisis averted. Thank God for modern psychiatry.
Except that he doesn't like the way the anti-psychotic drugs make him feel, so he goes off of them. And soon he's back to posting angry, disturbing diatribes that don't make a lot of sense, and this time, he refuses to go back to the hospital because he doesn't want to be locked up.
So now you're worried all over again. You know that you could call the police and they would come pick him up and take him back, but he's still mad at you for hospitalizing him the first time; you can only imagine how angry he'll be if he's hauled back there in handcuffs.
But he ends up in handcuffs anyway, not because he's accused of murdering someone, but because of drugs, or theft, or some other crime. And you're almost relieved because the terrible end that you thought was coming has finally come.
But maybe your kid doesn't end up in jail, but ends up living on the streets because he refuses to take your help -- anyone's help -- and now you don't even know where he lives. He stopped calling a long time ago when he figured you weren't going to keep giving him money, and he refuses to talk to anyone else in the family, even his brother, whom he was once close to.
And you'd like to get support for how heartbroken and guilt-ridden you feel, but you don't know where to get it because everyone assumes that you must have done something terribly wrong to have produced a kid who has such serious problems, or who wants nothing to do with you.
And no one believes that more than you, his mother or father, even though a meek voice of protest rises up inside you to try to unsuccessfully challenge the far more powerful accusing voice.
And watching the evening news, you recognize that while you're not the parent of a murderer, you feel an affinity for those parents far stronger than the parents of your friends with grandchildren, and children in college, or weddings to plan.
You know, like they know, that for all the lousy parents in the world, good people can still create children who do terrible things, or whose lives turn out in ways they never imagined, not in their worst nightmares.
And the image of that father the morning of the shootings, asking him what was in that black bag, knowing his son well enough to know that something was wrong, reminds you of all the signs you ignored or acted on, but apparently not well enough because now, look how things have turned out for you and your kid, your baby.
And no matter how many times you tell yourself it wasn't your fault, and however secure you are in that knowledge, it never buys you more than the briefest moment of comfort before you're back to blaming yourself and wondering, "How could I let this happen to my own child? What kind of a parent am I?"
The opinions expressed in this commentary are solely those of Joshua Coleman.