BRENTWOOD — The large police response to a reported pistol-whipping in Newmarket July 5, was ordered when law enforcement discovered the suspect had been researching bomb making and recently had a large quantity of ammunition shipped to his address, according to a police affidavit.

Geoffrey Sneirson, 30, is accused of pistol whipping a family member with a loaded handgun at his home at 804 Piscassic St., according to the affidavit submitted by Newmarket police Detective Scott Kukesh. The incident launched an hours-long SWAT operation in a densely populated part of Newmarket that afternoon.

The following day, Sneirson pleaded not guilty to a misdemeanor domestic violence charge in Rockingham Superior Court. He was also charged with domestic violence, first-degree assault, a felony charge. Judge Andrew Schulman said because Sneirson was not indicted on the first-degree assault charge, he did not have to enter a plea.

Sneirson will be held without bail as a result of his arraignment, but his attorneys could request a rehearing on bail pending the outcome of a mental health evaluation. The evaluation has yet to take place.

According to court documents, Sneirson had no prior criminal history.

The affidavit states Sneirson’s family member fled to a nearby address to call 911 to report the alleged assault just before 1 p.m. The victim was later transported to Portsmouth Regional Hospital for treatment, according to Newmarket police.

Multiple law enforcement agencies, including the Seacoast Emergency Response Team and Strafford County Tactical Team responded to the incident. Piscassic Street is part of the Twin Rivers condominium complex within a neighborhood of single-family homes, apartments and condos.

Police Chief Kyle True said officers attempted to contact Sneirson in person and by phone following the report of the alleged pistol whipping before requesting SERT assistance.

Unbeknownst to law enforcement, Sneirson had fled the home before the large police operation commenced, according to Newmarket police. Sneirson reportedly went north along the nearby railroad tracks and was apprehended along Route 108 in Durham by police with a loaded 9mm handgun in his possession at approximately 5:30 p.m., according to police

True told gathered media on July 5 said Sneirson was taken into custody “without incident,” but ended up being charged with simple assault of a police officer and resisting arrest by Durham police. Sneirson will be arraigned on the Durham charges separately in Dover District Court Aug. 16, according to the affidavit.

Residents of Salmon, River and Piscassic streets were instructed to shelter in place for the duration of the operation by law enforcement Thursday. Residents who had yet to return home were barred from doing so until the situation was resolved by around 6 p.m.

In addition to the two regional SWAT teams, Newmarket officers were assisted at the scene by New Hampshire State Police, the University of New Hampshire, Lee, Durham, Stratham and Rollinsford police departments. Newmarket Fire Rescue and McGregor Ambulance also provided assistance.