AUSTIN (KXAN) — Austin police are investigating two more possible rock throwing incidents from Monday night.

Starting at 11 p.m., the rocks were thrown within 45 minutes of each other. Police say they did not find any suspects. The first location was at Cesar Chavez and I-35. The second incident happened near the 3500 block of North I-35 between Concordia Avenue and 38 1/2 Street.

Police did make an arrest last week, but said they don’t believe the suspect was responsible for all of the cases. A man, identified as Marquel Boone, 44, walking on the sidewalk was arrested a few blocks away as he passed Dreamers, an adult entertainment store.

“Looking at the news where all the other people are brain dead, or broken collarbone, that’s really serious. That’s really serious,” said Terrell Hill, I-35 rock throwing victim. He admits he was lucky and hopes this arrest stops any would-be copy cat from throwing rocks.

MORE: Man suffers broken collarbone from rock

Austin police have created a new rock throwing tip line at (512) 974-7999. Victims of a rock throwing, however, are asked to call 911 immediately.

Police also said all rock throwing investigations will now be handled by APD’s Organized Crime Division.

The number of cases has almost totaled 90 since June 2014. During the weekend of May 20, 2016, police said 13 new rock-throwing cases injuring five people were reported. A week later, police upped the reward for information than can lead to an arrest and conviction to $25,000.

In hopes of keeping drivers safe, APD is utilizing the digital signs along I-35 from Martin Luther King to Howard Lane to warn drivers about rock throwing.