"In True Lassie Fashion" joke

A police officer came upon a terrible wreck where the driver and passenger had been killed. As he looked upon the wreckage a little monkey came out of the brush and hopped around the crashed car. The officer looked down at the monkey and said “I wish you could talk. ”
The monkey looked up at the officer and shook his head up and down.
“You can understand what I’m saying? ” asked the officer. Again, the monkey shook his head up and down. “Well, did you see this? ”
“Yes, ” motioned the monkey.
“What happened? ”
The monkey pretended to have a can in his hand and turned it up by his mouth.
“They were drinking? ” asked the officer.
“Yes! ” the monkey motioned.
“What else? ”
The monkey pinched his fingers together and held them to his mouth.
“They were smoking marijuana? ”
“Yes. ” the monkey confirmed.
“What else? ”
The monkey motioned “Screwing. ”
“They were screwing, too? ” asked the astounded officer.
“Yes. ”
“Now wait, you’re saying your owners were drinking, smoking and screwing before they wrecked. ”
“Yes. ”
“What were you doing during all this? ”
“Driving” motioned the monkey.