A trio of Chinatown necklace thieves were partially thwarted Monday, when two of them were captured mid-heist.

At 11:35 a.m. Monday, two women, aged 50 and 67, were on the 1100 block of Stockton Street, which is between Jackson Street and Pacific Avenue, according to the San Francisco Police Department.

Suddenly, police say, a 19-year-old man attacked the 50-year-old, throwing her to the ground and attempting to tear her necklace off. He was unsuccessful, however, as a witness "tackled [the suspect] to the ground and held him there until police arrived."

A second suspect then sprang upon the 67-year-old woman, who "was close by, observing the incident," police say. That suspect managed to snatch her necklace and jade pendant, leaving "marks and redness to [her] neck." He fled, and remains at large.

But though that ruffian escaped, a third did not. According to the SFPD, witnesses directed responding officers to a yet another suspect, an 18-year-old man police say "was the lookout" for his colleagues.

According to the SFPD, the suspects used a 2012 Chevy Captiva during the commission of their crimes. Though two of the alleged miscreants were arrested, police remain eager to capture the third. If you know anything about this case, they ask that you call SFPD's Anonymous Tip Line at 415-575-4444 or to text a tip to TIP411 with SFPD at the beginning of the message.