A 21-year-old man has been arrested after Santa Rosa police say they believe he is linked to the deaths of two high school students who died from possible fentanyl overdose.

Santa Rosa police investigators said on Monday they're conducting multiple investigations into the overdose death of two high school students, and the poisoning and hospitalization of two others, all due to fentanyl.

Two makeshift memorials, separated by just 3 miles, stood solemnly at the entrances of Santa Rosa and Montgomery high schools Monday morning. Adorned with flowers, handwritten notes and heartfelt messages,