PACIFICA (CBS SF) — Two people were arrested Thursday in Pacifica in connection with several drug-related crimes following the death of a man last year from an overdose of fentanyl.

Ronald Johnson, 50, and Lisa Anderson, 48, were arrested on suspicion of sales of a controlled substance, maintaining or operating a drug house, conspiracy and inflicting great bodily harm, according to the San Mateo County Sheriff’s Office.

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In March, deputies began an investigation into the death of Aaron McGregor, a Montara resident who died last year from a lethal dose of fentanyl.

Investigators identified two suspects responsible for selling McGregor the fentanyl, deputies said.

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On Thursday, detectives obtained arrest warrants for Johnson and Anderson and a warrant to search their residence in Pacifica.

Both suspects were taken into custody without incident, and a search of their residence resulted in the seizure of 15 firearms, suspected fentanyl and additional paraphernalia, deputies said.

Weapons seized at Pacifica drug suspects Johnson and Arruabarrena (San Mateo County Sheriff)

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Code enforcement for the City of Pacifica was also notified and responded to the scene. The residence was red-tagged for a variety of violations.