"It is true our officer was caught on camera and we'll take action against him," Mangira told The Standard.
He said one of the teachers realised she had lost money on her way home when she stopped to buy some goods.
After reporting the matter to the school principal, CCTV footage was retrieved and it showed the officer entering the room and ransacking bags belonging to three teachers.
Mangira said the three teachers lost Sh100, Sh300 and Sh900, respectively. The school reported the matter at Kimulot police station.
The incident has sparked protests from officials of teacher unions who are demanding the arrest and prosecution of the officer.
Kenya National Union of Teachers branch executive secretary Malel Langat called for action against the officer.
Describing the incident as embarrassing, Langat said it is embarrassing seeing an officer who is supposed to provide security stealing.
Langat said the officer should be arrested and legal action taken against him without further delay.
"He should also be made to return the money. The behaviour should be punished harshly to discourage such acts in future," said Langat.
In the video that has gone viral, the officer is seen walking into a room and ransacking bags, and stashing what seems to be money in his pockets.
Mangira called for calm, saying no stone will be left unturned in ensuring the officer faces the law for his deeds.
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