San Francisco cop arrested on suspicion of building illegal AR-15-style rifle

Thomas Abrahamsen, a San Francisco police officer, was arrested and will face firearms charges.
(San Francisco Police Department)

A San Francisco police officer has been arrested on suspicion of assembling his own illegal AR-15-style assault rifle, officials announced Wednesday.

Officer Thomas Abrahamsen, an 18-year veteran of the department, surrendered to authorities Tuesday and was booked and will face two felony weapons charges, San Francisco police said in a statement.

Abrahamsen, 50, is accused of violating a state law against assembling an assault rifle or weapon capable of firing a large .50-caliber BMG bullet.

Under a law approved by Gov. Jerry Brown on July 1, rifles with a “bullet button” that allows for a clip to be dropped with the press of a button and quickly replaced were banned. The law Abrahamsen was charged with violating would include an AR-15-style rifle modified with a bullet button or any weapon that fired the large BMG bullet.


The department’s Internal Affairs division had been investigating Abrahamsen since last summer, officials said.

“In the spirit of the Not on My Watch initiative, Department members will continue to hold each other accountable and will act swiftly to report any behavior that might bring dishonor to the Police Department,” acting Police Chief Toney Chaplin said.

The Not on My Watch initiative was launched by the previous police chief after the department was rocked by a series of scandals, including revelations that dozens of officers had exchanged text messages loaded with homophobic and racist language discussing the communities they served.

Several officers have been fired or resigned over the last 18 months because of the discoveries.

Abrahamsen is on unpaid leave and being held on $150,000 bail. Jail records show his arraignment is scheduled for Wednesday afternoon.

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2:10 p.m.: This article was updated with details of the accusations against Abrahamsen.

This article was originally published at 10:40 a.m.