Dariyon Keandre Lusk, 20, was arrested Monday. He was charged with aggravated robbery with a deadly weapon and aggravated kidnapping.
Police believe Lusk and 19-year-old Darrell Wayne Caldwell, Jr. were in a black Nissan Maxima that pulled up alongside a woman at the intersection of Highway 820 and Campus Drive earlier this month.
They pointed a shotgun at her and forced her to follow them to a Goodwill parking lot, where they robbed her.
Fort Worth police said the suspects made a couple of big mistakes in the days following the crime.
According to the arrest warrant affidavit for both men, the next morning, Lusk tried to sell the victim's cell phone, and before he did, he turned it on, activating the Find My iPhone feature.
According to the affidavit, "Dariyon Lusk presented his Texas driver's license to sell an iPhone 6 at the date, time and place the victim's phone was activated."
In another incident, the suspects shot a woman in the foot as she drove past 820 and Anglin Drive, police said.
Caldwell was taken into custody last week on aggravated robbery charges. He's now also facing charges for aggravated kidnapping.
Detectives seemed to get the most help from a confidential informant.
That person told police that a car abandoned in south Fort Worth last week was the same one seen in surveillance video from the first robbery, and the car was registered to Caldwell.
Then, the informant told detectives that Caldwell was the one who used a shotgun in the second incident.
The informant also told detectives about overhearing a chilling conversation from one of the suspects.
According to the affidavit, the informant "reported that a male called Dre or Lusk had been heard saying, ‘We should have killed that [expletive.]'"
The informant said he was talking about the kidnapping victim.