A lady on probation, working 4.5 weeks, go home without closing the door to the shop and leave her keys hanging in the door. Sliding door wide open. 45 Minutes later the owners is alerted to this by a customer in front of the shop.

The lady is a clock watcher and can not go home fast enough in the afternoons. She must go to the premises next door to sign out for the day. She left the shop in a hurry, signed out and got into her car and left. The shop were found open on a few occasions during this time, but there never was proof that it was her. This time there is no other explanation, as she left her keys in the door as well.

Priors:
Second appraisal (2 weeks ago) warned her of forgetting to lock doors, resulting in poor security standards.
Written warning: Poor work performance in that not paying attention to detail.

Questions.
Does this warrant a dismissal?
Do you have to suspend with pay till the hearing, even with such gross negligence and being under probation?