Cops Say Kendall Jenner's Alleged Stalker Can't Be Confined for Long

Kendall Jenner's alleged stalker is making his way through the criminal justice system, but the problem is ... even if he gets the book thrown at him, he could be out within days.

Law enforcement sources tell us, it doesn't really matter 37-year-old John Ford has repeatedly trespassed on Kendall's property in her gated community ... he's only charged with misdemeanor criminal trespass and the max he can get is 6 months in jail -- but, because of overcrowding, L.A. County Jail is a revolving door, and he'd almost certainly get out within days.

Ford, a Canadian citizen, would not be deported, because he's not charged with a violent felony.

TMZ broke the story ... Ford has repeatedly scaled the mountainside of Kendall's gated community ... once ended up by her pool and another time on her porch before he was nabbed by cops. He was placed on a psychiatric hold but released in 36 hours, because a psychiatrist found him mentally stable.

Ford was re-arrested Thursday for criminal trespass and held on $30k bail. He'll be arraigned soon, but a judge could release him on his own recognizance pending trial.

The best Kendall can do ... a civil restraining order, which she's getting. If Ford violates that order, he can be arrested. Again, the problem, the justice system becomes a revolving door. Realistically the most effective step she can take is to hire private security.