LA JOYA, TEXAS (ValleyCentral) — Five days after the Texas Department of Public Safety abruptly dropped all charges against a La Joya Independent School District administrator, investigators remain tight-lipped about what happened.

The Department of Public Safety arrested La Joya ISD Interim Transportation Director Jose Alaniz on Thursday morning.

Within hours, investigators apparently concluded Alaniz hadn’t done anything wrong and dropped all charges against him.

“The arrest warrant and all charging documents listing him as a party were withdrawn by the arresting agency,” according to a statement released by La Joya ISD, “and Mr. Jose Luz Alaniz was excused from any criminal or civil liability.”

Alaniz returned to work Thursday afternoon.

Why investigators arrested Alaniz and how they concluded he was actually innocent remain unclear.

Asked about the incident, the Department of Public Safety told CBS 4 News to submit questions in writing. The Department of Public Safety didn’t answer the questions — and never explained what happened.

Documents filed with Hidalgo County suggest the investigation was conducted by the Regulatory Services Division of DPS, which oversees vehicle inspections.

According to affidavits signed by an agent with the Department of Public Safety, a La Joya ISD clerk provided a local businessman with VIN numbers for 58 school buses “on or about” Aug. 1.

The businessman used the VIN numbers to create school bus inspection records without actually inspecting the school buses.

Neither the affidavit nor a statement released by La Joya ISD on Thursday explains why they created fraudulent inspection records for the school buses.

La Joya ISD attorney Jaime “Jerry” Muñoz, though, said the clerk apparently became concerned the school buses needed to be inspected, but nobody was available to handle the inspections during summer break.

“This was a one-time, isolated incident,” Muñoz told CBS 4 News on Thursday. “The employee acted alone.”

The affidavits don’t include any indication the clerk or the businessman received money as part of the scheme.

At some point, the clerk told a La Joya ISD administrator what happened.

“In response, the district administrator directed the employee to communicate with representatives of the Texas Department of Public Safety and report the behavior,” Muñoz said on Thursday, when he read a statement about the incident during a school board work session. “Our district administrator further initiated an internal affairs investigation to determine who was involved and what action was taken.”

The clerk, Laura Rodriguez, 39, of Peñitas, contacted the Department of Public Safety.

Rodriguez said “that she wanted to come clean about the situation of the school buses,” according to the affidavit. During a recorded phone call, Rodriguez said that she obtained the fraudulent inspection records from Pablo’s Scrap Metal and Used Auto Parts, a business in Pueblo de Palmas.

The Department of Public Safety arrested Rodriguez and Jose Pablo Rios, 31, of Peñitas, the owner of Pablo’s Scrap Metal and Used Auto Parts.

Rodriguez and Rios declined to comment.

Investigators planned to charge Rodriguez and Rios with tampering with a governmental record and engaging in organized criminal activity.

The Department of Public Safety, however, dropped the engaging in organized criminal activity charges against them.

That left Rodriguez and Rios with just a single charge: tampering with a governmental record, a third-degree felony. If convicted, they face a maximum of 10 years in prison.