A 24-year-old man is accused of fatally stabbing his girlfriend inside a Needham apartment then driving 25 minutes to a family gathering at a restaurant and attacking his two parents Saturday.

Family members were able to tie up Benjamin Walsh after he stabbed his parents and held him inside the Millis restaurant until police arrived, authorities said during a press conference Sunday.

Once Walsh was in custody, police learned they should head to his third-floor apartment on Marshall Street in Needham and conduct a well-being check inside.

Police found the body of Walsh's 20-year-old girlfriend inside the apartment, Norfolk District Attorney Michael Morrissey said. She had been stabbed multiple times.

Authorities identified the woman Sunday night as Olivia Bergstrom of Needham. Walsh will be arraigned Monday in Wrentham District Court in connection with the Millis stabbings.

"It is anticipated that the defendant will be arraigned in Dedham District Court for the Needham murder subsequent to his arraignment in Wrentham District Court," the district attorney's office said.

The discovery of the body and the attack inside the restaurant began to unfold sometime around 7 p.m. Saturday when Millis police were called to the Primavera restaurant.

"When police arrived they found two individuals needing medical attention from stab wounds," Morrissey said.

Family members told police Walsh had stabbed his parents, who are both in their 50s. Police did not release their names. The father is in good condition, but the mother remains in serious condition at a Boston hospital.

It appears the Walsh family had a function at the restaurant. It is unclear if Walsh was invited or not.

As Walsh began to attack, other family members subdued the 24-year-old and tied him up, investigators said.

"Shortly after that period of time, police learned and gained information that it was necessary to do a well-being check at the defendant's apartment," Morrissey said.

Police found the body of Walsh's girlfriend inside the apartment at 64 Marshall St. Authorities have not determined how long she was dead.

It is unclear if the same knife used in the attack on Walsh's parents was the same knife used in the fatal stabbing, but Morrissey said detectives did retrieve a knife that is "of interest" to police.

Walsh is currently in police custody in Millis where he faces numerous assault charges in connection with the alleged attack on his parents. Investigators anticipate filing charges in connection with the killing in Needham.

Authorities declined to say if Walsh uttered any statements while in custody.

Millis Police Chief Chris Soffayer said the Walsh family lived in Millis their entire lives and are held in "high regard" by people in the community.

Needham Police Chief John Schlittler said Walsh and his girlfriend lived together in the Marshall Street apartment, but only for a short time.