San Rafael police are investigating a homicide after a man was fatally stabbed Monday afternoon outside a medical building in the city's Terra Linda neighborhood. Officers detained a suspect the same day and said there was no continuing threat to the public.

Where and when

The stabbing happened outside Northgate Medical Dental Center at 750 Las Gallinas Avenue, near Northgate Drive, according to San Rafael police. That corner sits in Terra Linda, just north of Highway 101 in central Marin County.

Dispatchers got the call just after 1 p.m. Monday on a report of a man who had fallen and was receiving CPR at the scene, police spokesperson Sgt. Justin Graham told CBS Bay Area. When officers arrived, they found the victim had been stabbed. He was taken to a hospital and died of his injuries, Graham said.

What police said

Graham said there were no eyewitnesses. A person who came upon the victim called 911 and helped with life-saving measures before first responders arrived. Police later said a suspect had been detained and that investigators were working with that person to determine what happened.

"We are working with that suspect to determine exactly what happened and what transpired in this particular case," Graham said, according to CBS Bay Area. He added that it was too early to identify a motive. Neither the victim nor the suspect was immediately named publicly.

KPIX reporting carried by partner stations similarly said a person was fatally stabbed in San Rafael on Monday and that police reported a suspect in custody.

What is still unknown

As of Monday afternoon's public statements, San Rafael police had not released the names of the victim or the suspect, any charges, or a detailed account of how the attack unfolded. Motive remained under investigation. Police emphasized that the suspect was detained and that there was no ongoing threat to public safety around the medical building.

Terra Linda's Northgate area mixes medical offices, shopping and residential streets along Las Gallinas Avenue. A daytime stabbing outside a clinic is the kind of incident that draws neighborhood concern even when police say the immediate risk has passed. Anyone with video or other information is typically asked to contact San Rafael police; the department had not posted a separate tip line in the initial CBS account.

This story is based on Monday's on-the-record statements from San Rafael police through CBS Bay Area and matching KPIX reporting. Identities, charges and a fuller timeline may follow in later police updates.