Nassau police say they've arrested a man who allegedly slashed an officer in the face with a pair of scissors after being denied entry to a Massapequa bar.

The incident began Saturday night at McCann's Pub and Grill. Police say the man, identified as 26-year-old Robert Savage, damaged a windshield wiper on a party bus near the bar after he was not allowed inside the establishment for acting erratically. Someone contacted the police, who approached Savage near his home.

When responding officers attempted to talk to the man, they say he pulled out the scissors, slashed an officer's cheek and attempted to stab him in the neck. He also allegedly bit a sergeant and threw her to the ground.

Police used a Taser to subdue Savage, who was arrested. He is facing charges of aggravated assault on a police officer, possession of a weapon and resisting arrest.

The officer and sergeant were treated for their wounds at the hospital. 

The man's mother, Josephine Savage, says her son was diagnosed with schizophrenia in 2011. She says his medications were not working Saturday night, so she contacted Nassau County's Mobile Crisis Unit, which helps people experiencing psychiatric behavioral issues. 

Savage says that after counselors evaluated her son, they told her there was nothing they could do. She now blames them for the incident, saying, "This is a mental patient that has no control, he's in a crisis right now, he's unstable... What I'd like to see happen is my son get the treatment he needs."

News 12 contacted the Mobile Crisis Unit for comment, but has not yet received a response.