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WHITE OAK, Pa. (KDKA) – Police in White Oak are investigating the armed robbery of a business Friday night.

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A business located in the 2800-block of Jacks Run Road was robbed by two black males that were armed with pistols, according to police in a post to the White Oak Police Department Facebook page.

The incident took place at approximately 9:15 p.m. Authorities say that the men wearing facemasks entered the business and demanded money while threatening the employees.

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Police were able to develop identities of those involved and within hours were able to obtain arrest warrants for four suspects. Two males and two additional females were suspected to be responsible for the robbery.

Three out of the four suspects were taken into custody Friday night. They are requesting the community’s assistance in locating the fourth suspect, who they have identified as Robert Edward Harper. The suspect is a 45-year-old, black male, 5’7″, 160 pounds. He currently has an active warrant for his arrest. He is considered armed and dangerous.

White Oak Police request any information regarding Harper by calling 412-672-9726.

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The McKeesport Police Department and Pennsylvania State Police assisted in the investigation.