Hayden Gerson appears in court for a scheduled hearing on December 15, 2016.

A suspect accused of opening fire on San Diego police, punching two officers in the face and attempting to choke a police dog in a SWAT standoff pleaded not guilty to three attempted murder charges on a peace officer. 

Hayden Gerson wore a jail uniform and appeared to have a number of bruises on his head when he faced a judge at the San Diego County Courthouse.

Gerson was formally charged with three counts of attempted murder of a police officer performing his duties, one count of resisting an executive officer and one count of harm to or interference with a police dog causing great bodily injury, according to the San Diego County District Attorney’s office. Two of those three charges have allegations of using a firearm in the commission of the crime. 

He faces an maximum of 44 years to life. 

Gerson was arrested Monday after a standoff in Clairemont that began with a domestic-violence call and quickly escalated.

“At some point, he started to become agitated and make delusional statements towards the officers,” SDPD Capt. Brian Ahearn said of the defendant.

Police said two SDPD officers were punched and choked by the suspect, as bomb squad and swat members were positioned outside Gerson’s house. Officers then called for backup, leading to an hours long standoff where rounds of gunfire were exchanged.

The two SDPD officers have been identified as Officer Brandon Gibson, a 5-year veteran of the department, and Officer Justic Tennebaum, a 9-year veteran of the department. 

Dozens of homes were evacuated from the neighborhood. Officers had previously attempted to use a taser and other non-lethal weapons which proved ineffective. After they deployed a K-9 to take Gerson into custody, the suspect allegedly started to bite and choke the dog.

Following the SWAT standoff, Gerson was hospitalized for injuries from the police dog. Two police officers were also taken to local hospitals for treatment of scrapes and bruises.

He will next appear in court on Feb. 22.