(CNN) If not for the sharp eye of a Houston resident, authorities say, a possible serial killer may have zeroed in on his next target.

But Jose Gilberto Rodriguez, a parolee suspected in three killings over the past several days, was taken into custody Tuesday morning, Harris County Sheriff Ed Gonzalez said.

Jose Gilberto Rodriguez, a registered sex offender, was taken into custody Tuesday morning.

"It's possible he was casing the neighborhood in search of his next victim," the sheriff said. "So thanks to the alert work of that citizen and swift action, we were able to get involved."

Gonzalez said the tipster spotted a suspicious vehicle early Tuesday. It was the same Nissan Sentra that police said Rodriguez was likely driving.

After that resident called police, authorities realized Rodriguez was still in the car. Following a 14-minute pursuit through the neighborhood, Rodriguez was taken into custody without incident.

Deputy Jorge Reyes, who initiated the traffic stop when the license plate came back stolen, said once Rodriguez realized he couldn't escape, he pulled over and put his hands out the window.

Deputies found a pistol in the car.

"He didn't say anything," said Reyes, who has been with the sheriff's office for 4 1/2 years.

Forensic information that would tell whether the handgun was used in any of the crimes won't be available until Wednesday, Det. David Crane of the sheriff's office said.

Rodriguez is accused of two of the killings, Crane said. A third possible holding charge of capital murder could be added Wednesday after Houston police look at the evidence. He is scheduled to appear in court Thursday.

The suspect was interviewed but didn't divulge much and made no admission of guilt, he said.

Rodriguez's arrest came hours after the sheriff warned of "a possible serial killer" on the loose.

Police alerted the public to Rodriguez's car and photo.

Rodriguez, 46, is a registered sex offender who is on parole. Police said he cut off his ankle monitor a few days before the first shooting.

The first victim, Pamela Johnson, 62, was found dead Friday night inside her home in northwest Harris County after her family called authorities because they couldn't reach her.

Johnson's car was stolen from her home and later discovered at a nearby mall. That's when the Harris County Sheriff's Office reviewed the mall's surveillance video and made a connection with the suspect.

Two other people were found dead at different mattress stores Saturday and Monday.

Authorities said they also believe Rodriguez robbed a Metro bus driver early Monday and shot a driver last week. The driver who was shot is in serious condition but is stable and able to talk with his family, officials said.

Police have not released a possible motive in the killings. Crane said there is nothing to indicate a connection between any of the victims.

Gonzalez said the suspect has family members that live in the neighborhood where he was captured.

Houston Police Chief Art Acevedo told reporters that authorities are trying to determine whether Rodriguez committed other crimes they don't yet know about.

He also said Harris County is looking to form a task force that would focus on parolees who had committed serious crimes.

"We've got to up our game, because there's not enough to deal with parolees," he said. "But we're going to change that."