A man and woman remained hospitalized in critical condition today with gunshot wounds they suffered when the latter's ex-lover shot them in a midday ambush outside a Costco in Chula Vista before killing himself with the same gun.

Angelina Perez, 32, and her 31-year-old boyfriend, Samuel Valdez, were putting groceries into the back of their car in front of the warehouse store in the 1100 block of Broadway with their infant child next to them in a stroller when Sean Illian, 48, approached and began shouting at them about 12:30 p.m. Monday, according to police.

As stunned bystanders watched, Illian drew a handgun and shot the couple several times each, then put the weapon to his head and pulled the trigger once more, Lt. Dan Peak said.

RELATED: 2 injured, suspected gunman dead following Chula Vista shooting in Costco parking lot

Medics took the three to UCSD Medical Center in San Diego, where Illian was pronounced dead about an hour later, Peak said.

As the gravely wounded couple underwent emergency surgery, police turned their uninjured baby over to the custody of family members.

Investigators determined that Perez had dated Illian before breaking up with him sometime last year, according to Peak.

"Per witness statements, the relationship between (them) ended badly," the lieutenant said.

A GoFundMe page has been set up for Angelina and Samuel's recovery.