AUSTIN (KXAN) — Following a string of 13 rock throwing attacks on Interstate 35 last weekend, leaving five injured, Austin police say they are considering closing the lower deck of the interstate as part of their strategy to stop the incidents. Police are investigating a total of 83 cases spanning June 1, 2014 to Sunday, May 22.

At a 3 p.m. press conference Wednesday, Assistant Police Chief Chris McIlvain said the department couldn’t go into the details of their investigation without compromising it.

He said thousands of hours have gone into the investigation so far, adding the police appreciate all tips, calls, suggestions and emails that have been sent to them. McIlvain asked no one to take matters into their own hands in an attempt to stop the person responsible. He also gave the following guidance for I-35 drivers:

Be aware of your surroundings on I-35. If you are going to travel on the lower deck of I-35, use the outside lane instead of the inside lane. If you can find an alternate route, such as the upper deck, use it. Police believe the rocks are being thrown from vehicles traveling in the opposite direction. Spread word of the rock throwing incidents to friends and family. If you become a victim, pull over immediately where it’s safe to do so. Call 911 right away and record the time of the incident. Do not touch any potential evidence, including the rock thrown.

“We will be the first ones to be insisting that the DA’s office, the judge and the jury throw the book at the person responsible,” McIlvain said. That person will face charges of aggravated assault and possibly attempted murder.

The Greater Austin Crime Commission is offering a $10,000 award leading to the arrest and conviction of a person involved. “Before someone dies, we’re pleading with someone to come forward and give us additional information,” McIlvain said.

Police want to add signage to I-35 warning drivers of the rock throwing incidents and giving instructions on what to do if you are a victim, which would benefit people driving through Austin who may not be aware of the cases.

When asked of the likelihood of shutting down portion of I-35, McIlvain answered, “At this point we are not ruling anything out. Based on the time of the day that these are occurring — being in the late night or early morning hours — potentially closing the lower deck and only using the upper deck through that time period is a possible strategy. I don’t see it as being the solution.” McIlvain says they will explore that option with TxDOT.

There have been a number of rock throwing cases away from the lower deck. Police say most of the cases are happening between 10 p.m. and 6 a.m.

Investigators do not know if one or multiple people are throwing the rocks.