Updated March 30: Revised to include suspect's booking photo.

James Earnest Floyd Jr. (Kaufman County Jail)

Authorities have arrested a Terrell sex offender after a husband and wife were shot during a home-invasion robbery in west Fort Worth on Tuesday.

That man, 50-year-old James Earnest Floyd Jr., also is suspected in a Dallas kidnapping on Sunday.

The Fort Worth shooting occurred around noon Tuesday in the 10200 block of Cool Spring Drive, near Old Weatherford Road.

The victims were identified as John and Diane Porter, both 69. Police said John Porter's condition was extremely critical.

West Division is responding to a robbery/shooting on Cool Springs Rd. Details to follow... pic.twitter.com/rFlAIVnn2t — Fort Worth Police (@fortworthpd) March 28, 2017

A Fort Worth police report indicates that a 911 caller said that she had been shot and robbed in her home. Police said the gunman stole a credit card and the couple's car, a light blue 2008 Kia Sorento SUV with an American flag in a rear window.

Around 6:15 p.m., police said a person of interest was in custody in Terrell. The Kia was found at an apartment complex in Terrell shortly later.

"Anytime you have a home invasion, it's disturbing," police Sgt. Marc Povero told KXAS-TV (NBC5). "This is what we would consider a random crime, which makes it even more disturbing. There's just no sense to a crime like this."

A car abandoned near the scene of Tuesday's robbery connects that case to Sunday's kidnapping, police told NBC5.

Around 3 p.m. Sunday, police said, Floyd kidnapped a man at gunpoint in the 1500 block of East Louisiana Avenue, near South Lancaster Road in east Oak Cliff.

Floyd drove to Terrell before releasing the man, who called police from a nearby home, police said. The victim told authorities during an interview that he knew Floyd.

Floyd is being held at the Kaufman County Jail on a kidnapping charge and a parole violation.

Floyd, who was convicted of the 1983 rape of a 19-year-old woman, has been a registered sex offender since his release from prison in 2011.