Dr. Pemulis's Good-Time Family Subway Solution: Totes Off Topic!!

So today riding the train, I was lost in thought. I was deeply troubled by a movie I had watched Sunday(as well as numerous times prior). The movie in question is Back to the Future Part II. Now, my quarrel has naught to do with any of the time travelling issues that might arise after a long thought about their logistics. My problem comes about a half hour into the movie. The police find Jennifer asleep, read her thumbprint, figure out who she is and decide to bring her home. Marty and Doc. Brown watch this situation unfold, and Doc. Brown says they can't intervene. He says something to the effect of "What do we tell them? That we're time travellers and she was asleep?!?!"

He then realizes the implications of what could happen once they bring her home: she encounters her future self, a time paradox occurs, universe explodes, cats and dogs living together, mass hysteria. Or something. The plan then is to intercept Jennifer at the house before she encounters her future self or anyone else.

My question is this: Couldn't they have just walked up to the cops and had Marty say "Oh that's my wife. Sometimes she sleepwalks." Then they read his thumbprint, see that he's telling the truth, then send them on their merry way? This literally has been driving me nuts for the past two days (one might say I need to get a life). But seriously, wouldn't that have been a viable option? The genius who invented a time machine cant invent up a little white lie to explain why a woman is sleeping on the street?

FUCK!