Surveillance cameras captured two robbers ambushing a couple outside their home.

The robbery happened at a home in the 16900 block of Northwest 52nd Avenue about 9 p.m. Saturday.

Two robbers slipped past a gate and waited 15 minutes outside the house until Jesus Alvarez arrived. As he got out of his car, the two men ambushed him.

"Gagged him, tied him up -- arms and legs," said his son, Jesus Alvarez Jr. "They caught him from behind."

While Alvarez, 71, lied on the ground outside, his wife, Miriam Alvarez, heard the commotion and confronted the men.

One robber punched her, and Alvarez, 68, hit her head on the driveway, knocking her unconscious. When her husband of 54 years escaped from his binds, video showed him kneeling next to his wife.

"These people are not human. They're animals," said Alvarez Jr. "To see something like this, it's heartbreaking to me and I'm pretty sure to a lot of people."

The robbers stole about $800 in cash.

"For some people, I understand that's money but that's not real money to do what they did," said Alvarez Jr. "We really want to get these animals off the street."

Jesus Alvarez

The couple was airlifted to Jackson Memorial Hospital. Jesus Alvarez was treated and released, and Miriam Alvarez underwent brain surgery on Friday morning, according to her son.

She's expected to remain in the hospital for the next seven months, said Alvarez Jr. Her 97-year-old father was also home at the time but he wasn't injured.

Anyone with information on the robbery is asked to call Miami-Dade Crime Stoppers at 305-471-TIPS.