SAN DIEGO—A suspect in two attempted child abductions at Westfield Mission Valley mall this week was arrested Thursday, several hours after the second of the two crimes occurred.

San Diego Police Department (SDPD) officers pulled over Rene Lujan, 42, at about 4 p.m. as he was driving on eastbound state Route 94 near Home Avenue in the Mount Hope area and took him into custody, SDPD public affairs Lt. Daniel Meyer told reporters.

Roughly two hours earlier, a bearded, dark-haired man who appeared to be in his early 40s grabbed a 5-year-old girl at the Camino Del Rio North shopping center and tried to put her into a dark-colored car before abandoning the attempt and driving off, Mr. Meyer said.

About 1:30 p.m. Tuesday, a man with a closely similar description snatched a 6-year-old as she was walking beside her mother and pushing her 8-month-old brother through the mall in a stroller, according to police. He then turned around and walked off with her in the opposite direction, the lieutenant said.

When the child cried out a moment later, the man put her down, ran off to the west and fled the area in a black 2013 Chevrolet Volt, according to police.

Investigators were able to identify Mr. Lujan—who is a stranger to both of the victim families—as the suspected abductor via the car’s license plate, Mr. Meyer said during a briefing at downtown SDPD headquarters.